In the recent Witney byelection, the Lib Dems recorded their biggest byelection swing in 20 years, though they still lost to the Conservatives. That was a test ground for more winnable seats like Richmond Park (Zac Goldsmith’s constituency), party sources said.

Recalling the byelection after the resignation of Lib Dem cabinet minister Chris Huhne, one senior Lib Dem source said:

Never mind Witney, this is going to be a bigger campaign than Eastleigh. In Witney we were going for a really strong second, which we achieved, this time we will be going to win.

The party expects 4,000 of its members in Richmond and neighbouring seats to campaign in the west London seat if Goldsmith resigns later on Tuesday.

If a byelection is triggered, the party will face an uphill battle for recognition in the seat. Vince Cable, the former business secretary who was rumoured to be standing in Richmond Park having lost the neighbouring seat of Twickenham, will not run in the byelection.

Instead, the candidate is a relative unknown, local accountant Sarah Olney who only joined the party in May 2015.

Olney told the Guardian she had initially expected just to be delivering a few leaflets, but now faces the prospect of fighting a tough by-election within months, having only been selected in July. She said:

This has been a bit unexpected. But I’m ready to go to the voters, and our activists are really fired up by the result in Witney, and want to get stuck in to another byelection.

The party was united in opposition to Heathrow, unlike the Tories, Olney said.

A Conservative government has approved the expansion, and it shows how he has been ineffective in fighting it.

Brexit will be the party’s other major talking point in west London too, with high numbers of EU citizens living in Richmond Park. Olney said:

It was a strongly remain area and Zac has let down a lot of his constituents in supporting the leave campaign. He is not representing their opinions at all, and it creates a great deal of uncertainty for residents.

The SNP’s Westminster transport spokesperson, Drew Hendry, has called on the UK government to ensure that Scotland gets a “fair deal” from Heathrow expansion.
Welcoming the decision, Hendry said:

There is still a long way to go before parliament even gets to vote on it - and the Tories are deeply and bitterly divided about it -so for businesses and travellers there will still be frustration.

Whilst expansion at Heathrow can and must benefit Scotland, there will be disproportionate benefit to the south east of England and London. The UK government must ensure that when this does eventually get approval Scotland gets a fair deal from the process. We should see a commitment on route investment, guarantees to Scottish cities and an equitable share of any public spending that might be accrued coming to Scotland.

For the wider benefit they must also make a proper commitment to supporting new airspace plans, bio fuels for aircraft and the use of carbon reduction technology.

But his counterpart for the Scottish Greens, John Finnie MSP, criticised the SNP’s support for today’s decision, insisting that “it does nothing to advance social justice”.

Finnie said:

Wealthy frequent fliers will benefit, as they will from Scottish Mmnisters’ desire to cut air passenger duty. Maintaining air links between cities as far apart as Inverness and London makes sense but that does not require expansion. The real priorities for our tourist industry are skilled workers, better rail and bus travel for workers and visitors, and better broadband and mobile reception. Those cheering today’s announcement are celebrating a backward step.

The Lib Dems are unimpressed by the protestations of some Conservatives:

Another senior Conservative has spoken out against the decision. The education secretary Justine Greening declared that she is “extremely disappointed”.

The MP for Putney, Roehampton and Southfields, said:

Along with many people in my local community, I am extremely disappointed with the decision to push ahead with a third runway at Heathrow.

My views against expanding Heathrow, particularly on the impact of noise and air pollution on local residents and the weak economic case, are long-held and well-known.

I will continue to represent the views of my constituents, not least during the forthcoming public consultation on the draft national policy statement announced by the secretary of state for transport today.

Here’s some more of what Boris Johnson’s said about the Heathrow decision

The foreign secretary claimed the project would cause “inevitable degradation” to the quality of life of people under the potential new flight paths.

He said:

A third runway is undeliverable. The day when the bulldozers appear is a long way off, if indeed they ever materialise.

(Johnson had previously promised to lay down in front of bulldozers to prevent a third runway being built.)

Johnson said the new runway would create a “hell” of aircraft noise above London, moments after pausing the interview to wait for a passing jet, and suggested that his plan for a new airport in the Thames Estuary was a “better solution”.

He said:

No other great city would do this to its inhabitants. New York is going to be the city of beautiful skyscrapers, Paris the city of lights and London in the future, if we go ahead with this project, will be known as the city of planes.

He anticipated the proposal would be “snarled up” in legal cases and pointed out that it was not the first time a government had given its approval to Heathrow.

I think it very likely it will be stopped. We have been here before and we are going to see an inevitable fight in the courts and I think the chances of success for the proponents of the third runway are not high.

Zac Goldsmith stood up in the Commons after Grayling’s statement and condemned the decision but made no mention of his plans to resign.

The government has chosen a course that is not only wrong, it is doomed. It’s wrong because of the million people who will suffer on the back of the environmental harm this project unavoidably produces and doomed because of the complexities and costs and legal complications means this project is almost certainly not going to be delivered.

I believe this will be a millstone around this government’s neck for many, many years to come, constant source of delay, of anger and betrayal among those people who will be directly affected.

Goldsmith said he “would not know where to begin” in questioning the decision. “I simply want to put my absolute opposition on the record.”

Grayling said he respected the sincerity of Goldsmith’s views and his commitment to his constituents.

I hope he will at least respect the fact that all of us in politics have to do what we believe is right, I am doing what I believe is right,” he said. “His views are what he believes is right. Not all of us can get it right all the time, but you have to do what you believe is best for your country and that is what I believe I am doing now.

Campaigners opposed to Gatwick’s expansion have expressed relief at today’s decision.

Sally Pavey, chair of CAGNE, Communities against Gatwick Noise and Emissions, said:

This clear decision will put an end to the years of uncertainty for our communities and the country. Gatwick expansion was always the wrong choice both from a national and a local perspective.

Nationally, had Gatwick been chosen, Britain could not have competed with Europe’s excellent transport hubs because we would have had two inadequate hubs 40 miles apart with little or no connectivity. Locally, it would have brought our infrastructure to a standstill, destroyed our ancient woodlands, heritage sites, and areas of outstanding natural beauty, added numerous new flight paths over areas previously undisturbed and doubled flights over our skies night and day with no respite.

She urged Gatwick airport to accept the decision.

This animation shows the layers of air traffic associated with each of London’s five major airports over a 24-hour period. In Heathrow’s case that will obviously expand if a third runway is built.

Shadow transport secretary Andy McDonald begins by condemning the fact that the decision was widely leaked in the media ahead of being sent to him and announced to the house.

He also criticises the “procrastination and delay”.

He stresses that Labour’s support will be conditional:

Firstly, on sufficient capacity being delivered; secondly, that the UK’s legal climate change obligations are met; thirdly, that local noise and environmental impacts are managed and minimised; and fourthly, that the benefits are not confined to London and the South East.

Grayling says:

This is a decision in the national interest, it is not just about south-east England.

There are laughs as Grayling denies that the process has been slow and convoluted, claims he blames on the media.

He acknowledges “strong feelings” both for and against a third runway at Heathrow.

He finishes by saying that it is vital for the future prosperity of the country.

Grayling says the government is backed by UK airlines and businesses that a third runway at Heathrow is the right option.

He stresses that Gatwick remains “a key part of out transport infrastructure and will continue to be so in the future”.

There must be efforts to make Heathrow “a better neighbour”.

He says the government takes the issue of air quality “very seriously indeed”.

By the time a new runway is built he hopes to have made substantial progress in tackling air quality concerns, says Grayling.

He says aeroplanes are being made quieter and, referring to the 6.5 hours ban on flights each night, claims that even with expansion fewer people will be affected than today.

Heathrow will pay 25% above the market price to people whose homes have to be demolished as well as all costs, including stamp duty.

He says it is not “expansion at any cost but the right scheme at the right cost”.

Grayling begins his statement in the Commons saying if we do nothing the costs to the economy will be significant.

Any one of the three plans would have brought benefits but a third runway at Heathrow was the clear decision of the Airports Commission, he continues.

The government has decided to accept that recommendation.

He says it offers the greatest benefits to passengers and businesses.

Crucially it comes with world-leading measures to limit the impacts on those living nearby.

Labour said it still needed “vital reassurances” before backing Heathrow, even though it said airport expansion was “much needed” for investment and growth.

Shadow transport secretary, Andy McDonald, said:

Labour has consistently been in favour of building an additional runway in the south east of England. But this support has always been conditional on four tests being met: on capacity, climate change, noise and air quality and the wider national benefits. Today’s announcement, heralding another consultation, does not yet do that.

Shadow chancellor John McDonnell says the decision is a “disaster”:

The Scottish government has faced considerable criticism since it announced its backing for the third runway, which it claimed would create up to 16,000 jobs across Scotland.

A memorandum of understanding was signed at the start of October between London Heathrow airport and the SNP government, containing a series of commitments, including the one on jobs, investigating the use of Glasgow Prestwick airport as a potential site for a logistics hub for building the third runway, and a reduction of £10 per passenger on landing charges paid by airlines operating services from Heathrow to Scotland,

The memorandum was signed just days before the SNP’s party conference, which included a “private, airport-style lounge” sponsored by Heathrow to promote the benefits of the expansion to Scotland, as it did at last year’s event in Aberdeen.

Although Heathrow also supported recent Labour, Tory and LibDem conferences, no other party formally backed the expansion in this way. But the Scottish government insisted it had engaged extensively with both Gatwick and Heathrow’s proposals, and the latter’s offered the best deal for Scotland.

At the time, environmental campaigners also expressed their disappointment that the Scottish government failing to match its climate change commitments with action.

Following today’s news, the Scottish Liberal Democrat transport spokesperson Mike Rumbles MSP added to the criticism, sayings:

The SNP have utterly failed to square their backing for Heathrow with their climate change commitments and ambition to reduce environmentally damaging short-haul flights.

This seems surprising given that Boris Johnson said, as he left Downing Street, that he would continue to fight against Heathrow expansion. We know Justine Greening is opposed to a third runway as well.

Neil Keveren, whose house faces what is scheduled to become the boundary fence of the new runway, said residents felt “betrayed” by the decision, six years after David Cameron gave a commitment that a third runway would not be built at Heathrow, “no ifs, no buts”.

We received a promise. We all made life choices based on that, which we believed. Some people decided to lay their loved ones to rest here because of it. I invested in my home. I thought we were safe and I feel we have been have been betrayed by Theresa May.

Half of the ancient village is set to be flattened to make way for the runway, with most feeling the remainder of the village will become unliveable.

“I’m very disappointed, and I feel betrayed, and also worried,” said Lesley O’Brien, whose house in Cambridge Close, in which she has lived or 46 years and raised her three children – is scheduled to be bulldozed.

“Where can I go? They keep on about the money, but it’s not about the money. They can keep their money. I want to stay here.”

Despite the thundering M4 and M25 just to the north and west, Harmondsworth is a historic and pretty community, and many who lived here have very local roots. Dave Durston, who moved here in 1983, grew up and went to school just a few miles away. What angered him, he said, was “the fact that people who live nowhere near the place, without coming to see what’s going to be destroyed, can decide that it’s got to go”.

Somewhat incredibly, the government has suggested the third runway at Heathrow would help reduce carbon emissions:

Officials have also claimed the third runway would be not see the UK breaching legal air quality limits, because of mitigation measures such as electric car charging points and more public transport.

Lib Dems leader Tim Farron said the government has betrayed communities in west London.

The ‘No Ifs, No Buts’ pledge from the Conservatives has been thrown by the wayside in the rush to bulldoze homes and build a new runway.

Zac Goldsmith has failed Richmond Park on Heathrow and betrayed them on Brexit.

The turbulence in the Conservative party is nothing compared to the anger felt by those they have betrayed by giving up their commitment to the environment and communities in West London.

Theresa May used to make this case, now she has ripped those words down from her website and scrubbed them from history.

Boris once said he would lay down in front of the bulldozer. Now he will find himself on the slow boat to China - anywhere to avoid having to stand up for his principles - or stand down from his seat at the cabinet table.

Here is Chris Grayling explaining Heathrow was chosen to boost connectivity to the rest of the UK and to provide the best trade links to the rest of the world.

The mayor of London, Sadiq Khan, accused the government of “running roughshod over Londoners’ views”, saying he had been elected on a clear platform of opposing a new runway at Heathrow.

He said:

A new runway at Heathrow will be devastating for air quality across London – air pollution around the airport is already above legal levels of NO2.

Heathrow already exposes more people to aircraft noise than Paris CDG, Frankfurt, Amsterdam, Munich and Madrid combined. A third runway would mean an extra 200,000 people impacted, exposing 124 more schools and 43,200 more schoolchildren to an unacceptable level of noise.

This is what has been given the go ahead:

Back Heathrow’s campaign director, Rob Gray, said:

This is a significant moment for thousands of residents living near Heathrow who back expansion because they have waited a long time for today’s news.

It’s now or never. Building a new runway at Heathrow has plenty of cross-party support in parliament and backing from the majority of international airlines, business groups, trade unions, exporters and communities surrounding the airport. This is a golden opportunity for the UK that must not be squandered.

The leader of Richmond Council said he is “appalled” by today’s decision. He promised to “fight this threat, using every means at our disposal within the law” and that the third runway would never be built.

The government said it will propose a six-and-a-half hour ban on scheduled night flights, and will make more stringent night noise restrictions a requirement of expansion. It will also propose new legally binding noise targets.

It also stipulated that the third runway “must be delivered without hitting passengers in the pocket”. Although charges to airlines are expected to rise substantially at an expanded Heathrow, the government said that the Airports Commission and CAA were clear that keeping fares steady was “achievable”.

Airlines warned that the cost of expansion would be crucial. Airline trade body BATA said:

We will be scrutinising this decision and future, more detailed, plans. Heathrow is the most expensive hub airport in the world - and airports are not funded by the taxpayer, but by passengers. Today’s passengers must not pay for capacity that will not be operational until the mid-2020s.

Armelle Thomas has lived in Harmondsworth since the late 1960s - she and her late husband Tommy met while working at Heathrow and “fell in love” with the village.

Her house, just behind the High Street, is one of those set to disappear under the new runway, but Thomas said she was determined never to move.

My house is not for sale at any price. I was with my husband for 46 years and I have my memories.

Last month, she attended the Conservative party conference to hand out protest leaflets.

Nobody is talking about 10,500 people being made homeless by a government that is supposed to be compassionate. I’m a Conservative, I have always been, but they will never get my vote again.

Another local resident said his elderly neighbour in their home village of Longford, which will disappear entirely to make way for a car park, had been in tears when he spoke to him this morning

The man, who declined to give his name because he works at Heathrow, said his neighbour visited hospital every second day because he needed dialysis.

Where is he going to move to? He’s not going to find another house, another village. He has there since before Heathrow, he grew up there. He will never have people supporting him like they do in the village when he is sick. It’s totally unfair on people like him.

Business leaders have welcomed the decision to expand Heathrow. The president of the CBI, Paul Drechsler, said it was “an enormous relief to firms in every corner of the country”.

He said:

It will create the air links that will do so much to drive jobs and unlock growth across the UK.

With contracts to tender for, apprentices to recruit and supply chains to build, this decision must be taken forward swiftly, giving businesses the confidence to invest.

The chair of the transport select committee, Louise Ellman MP, said:

This decision will boost business, create training opportunities and new jobs and open the UK to new markets.

We have had to wait a long time for this. We recognise it won’t be an easy journey… We urge the Government to have the courage of their convictions and press ahead so that the timetable to deliver the additional capacity by 2030 can be delivered.

But Jonathan Bartley, co-leader of the Green Party, said:

The decision to expand Heathrow tramples over the concerns of local people and puts a wrecking ball through the Government’s claim to be concerned about climate change. The truth is that the Government went into this process with their eyes shut to the only sensible option: stopping airport expansion.

The Campaign to Protect Rural England said it was “madness”. Ralph Smyth of the CPRE said:

The north-south divide has been increasing: by giving the go ahead to yet another runway in the south the Prime Minister has effectively pulled the rug on her own flagship policy of rebalancing our nation’s economy.

It’s madness to be promoting domestic flights at the same time as investing in alternatives like high speed rail.

Heathrow is naturally pleased with the decision.

A spokesman for the airport said:

We welcome the news that Heathrow is government’s preferred site for a new runway and look forward to hearing the full details later from the transport secretary.

Expansion of Heathrow is the only option that will connect all of the UK to global growth, helping to build a stronger and fairer economy.

We await the full details, but Heathrow stands ready to work with government, businesses, airlines and our local communities to deliver an airport that is fair, affordable and secures the benefits of expansion for the whole of the UK.

It is understood Justine Greening, the education secretary, will restate her opposition to expansion at Heathrow in a statement for constituents later on Tuesday afternoon.

She is not expected to give any broadcast or press interviews. Under the terms of May’s limited suspension of collective responsibility, Greening will be able to continue expressing her discontent with the decision without actively campaigning against it.

Zac Goldsmith, the Tory MP for Richmond Park, said he was meeting constituents about the “catastrophic” decision before making a statement on his future this evening.

He has threatened to resign and trigger a byelection in his seat, standing as an independent, but has not yet said whether he will do this straight away or put it off until there is a vote in parliament next year.

Leaving Downing Street, Grayling was asked if he truly believed the third runway would become a reality. He answered: “Absolutely.”

The Campaign for Better Transport said the decision to back a third runway was scandalous.

Chief executive, Stephen Joseph, said:

It’s scandalous that the government has completely ignored the environmental impact of a new runway, or the costs it will impose on people on lower incomes with the huge sums the Airports Commission proposes adding to the cost of plane tickets to allow a new runway to be built. There is also the huge cost to the taxpayer of providing the addition surface access to Heathrow, which Transport for London’s own research shows is likely to be at least £17 bn, and how this will siphon off money from other schemes to tackle London’s already overcrowded transport network.

The charity is calling for a frequent flyer levy to reduce the growth in demand for flights which is says comes from a small, wealthy minority, and thereby remove the need for a new runway.

Friends of the Earth’s head of campaigns Andrew Pendleton, who lives under the flightpath in west London, said:

Expanding Heathrow would be a hugely damaging blow for local people, and makes a complete mockery of government commitments to tackle climate change. With the government poised to sign the Paris climate agreement, it’s decision to expand Heathrow – shortly after forcing fracking on the people of Lancashire – looks deeply cynical.

He warned:

However this is only the first step on a long journey that will see communities, councils and climate campaigners continue the battle to reverse this misjudged and damaging decision.

Confirming the decision to build a third runway at Heathrow, transport secretary Chris Grayling says the government has made a “momentous” decision today:

The step that government is taking today is truly momentous. I am proud that after years of discussion and delay this government is taking decisive action to secure the UK’s place in the global aviation market – securing jobs and business opportunities for the next decade and beyond.

A new runway at Heathrow will improve connectivity in the UK itself and crucially boost our connections with the rest of the world, supporting exports, trade and job opportunities. This isn’t just a great deal for business, it’s a great deal for passengers who will also benefit from access to more airlines, destinations and flights.

This is an important issue for the whole country. That is why the government’s preferred scheme will be subject to full and fair public consultation. Of course it is also hugely important for those living near the airport. That is why we have made clear that expansion will only be allowed to proceed on the basis of a world class package of compensation and mitigation worth up to £2.6 billion, including community support, insulation, and respite from noise – balancing the benefits and the impacts of expansion.

The Department for Transport said a new runway at Heathrow will bring economic benefits to passengers and the wider economy worth up to £61 billion. Up to 77,000 additional local jobs are expected to be created over the next 14 years and the airport has committed to create 5,000 new apprenticeships over the same period, it said.

The DfT pledged “a world class package of compensation and mitigation measures for local communities”.

It looks like we will be waiting at least until this evening for Zac Goldsmith’s promised resignation in the event that a third runway at Heathrow was given the go ahead.

A Labour source said:

Seems the way the country is finding out about the decision on Heathrow is through a series of leaks - sums up the government’s disregard for those affected.

Other cabinet members have also been responding to the apparent choice of Heathrow:

Boris Johnson appears to have confirmed the decision, leaving Number 10:

A decision that a third runway will be built at Heathrow paves the way for hundreds of thousands more flights a year at the London airport.

In the long-awaited response, the government looks as if it has endorsed the recommendation of the Airports Commission to expand Heathrow rather than Gatwick airport, which had hoped to build a second runway.

The move comes six years after the Conservative-led coalition scrapped previous plans for a third runway at Heathrow.

The decision to grow Heathrow will be voted on by parliament in 2017 or 2018. Under the airport’s proposed scheme, an additional runway and a sixth terminal will be built to the northwest of the existing airport perimeter at a cost of £17.6bn, demolishing the nearby village of Harmondsworth.

Widespread protests and legal challenges are expected to follow the decision, with campaigners expected to focus on air quality, noise and Britain’s climate change commitments. The runway, which could be built by 2025, would mean almost 50% more planes over London, bringing new neighbourhoods under the flightpath.

John Stewart, chair of the campaign group HACAN, which has been fighting a third runway at Heathrow, said:

As expected, permission for a new runway has been made dependent on certain legal conditions being met. HACAN will fight for the implementation of these measures whether we get a third runway or Heathrow ultimately remains a two runway airport.

Countless residents will be dismayed and distraught by this decision. Some will lose their homes. Some face the daunting prospect of living under a noisy flight path for the first time. And many others will get yet more planes over their heads. But real doubts must remain whether this new runway will ever see the light of day. The hurdles it faces remain: costs, noise, air pollution and widespread opposition including an expected legal challenge from the local authorities.

Looks like we’re going to be kept waiting for transport secretary Chris Grayling’s official confirmation of the decision...

Lib Dems are protesting outside Downing Street against a third runway at Heathrow.

Green party MEPs believe it’s a done deal in favour of Heathrow (as the BBC is reporting citing anonymous sources).

Keith Taylor, Green MEP for the south east, who sits on the European Parliament’s transport committee, said:

There are no two ways about it; this is a disastrous decision for the people of the south east, London, Britain, and the planet. Welcome to Theresa May’s never-never land, where prime ministers never have to listen to scientists and never have to apologise for increasing CO2 emissions and air pollution levels.

The Maidenhead MP has flip-flopped on her previous opposition to Heathrow and has kowtowed to the demands of multi-million-pound airport lobbies while ignoring the concerns of her own constituents and the need to take urgent action to mitigate catastrophic climate change. Is this what the prime minister had in mind when she promised to build a Britain not driven by the interests of a privileged few?

Jean Lambert, Green MEP for London, said:

Contrary to all the evidence Theresa May has decided to forge ahead with the expansion of Heathrow airport regardless of the dreadful impact this will have on the local community, London and indeed the planet.”

This decision is clearly incompatible with Britain’s recent agreement to ratify the Paris agreement and will further contribute to air pollution for my constituents in London and beyond.

This is the message from Clear Air in London:

It is probably too late for this...

The BBC’s political editor says Heathrow has got the green light (which is what most people are expecting).

The meeting of the airports sub-committee has taken place, which means a decision has been taken ...but we await the details of what it is.

Theresa May is currently communicating her decision to the cabinet.

Green party co-leader Caroline Lucas is at the protest outside the Houses of Parliament. She says the message is “expanding aviation is not compatible with ...climate change objectives”.

Lucas has not ruled out taking direct action herself.

Protesters against airport expansion have been making their point outside the Houses of Parliament this morning.

WWF UK and Friends of the Earth have both criticised the decision to approve new runway capacity.

WWF UK’s director of advocacy, Trevor Hutchings, said:

Expanding airport capacity makes little business and no environmental sense. The government plans to ratify the Paris treaty, committing us to reduce the UK’s carbon footprint – and just weeks ago it helped to broker a deal that aims to reduce emissions from international aviation. Bringing more air traffic to London’s busy airports flies in the face of that objective.

Before any concrete is poured the government should publish a credible plan for driving down aviation emissions. And its industrial strategy must unequivocally commit to low-carbon growth, providing long-term clarity for investors in clean energy, infrastructure and transport.

Friends of the Earth’s head of campaigns Andrew Pendleton, who lives under the Heathrow flightpath in west London, said:

We won’t tackle climate change if Heathrow or Gatwick airports are allowed to expand.

Expanding airports anywhere will cause more noise and air pollution, with millions of people under flightpaths facing hundreds of extra flights every day.

Ministers must realise that signing the Paris agreement requires action too. We can’t keep giving the green light to climate-wrecking activities such as more flights and fracking.

Whatever the decision, campaigners, communities and councils will continue the fight against airport expansion - and the pollution and misery this would bring.

Sandeep Chopra, who has run the village shop in Harmondsworth for the past six years, said the decision to build a third runway at Heathrow, forcing the demolition or evacuation of most of the village, would “destroy my life”.

I will lose everything - my business, my house. It’s not easy going somewhere and starting again.

As a leaseholder, he said, he did not think he would be entitled to compensation.

I have a large family, we don’t take anything from the government in housing benefit or anything like that, and we all depend on this shop.

That included his wife and theee children, his parents, sister and brother, he said.

Harmondsworth is “a proper village”, he said, pointing to the large reservoir nearby, the two village churches and the medieval barn, run by English Heritage.

It’s a residents’ shop. People love the community, and they support us.

Greenhouse gas emissions could consume around half the carbon budget available to the UK in 2050, even if the sector’s emissions growth is constrained, according to analysis by Carbon Brief.

It says:

In its most recent forecasts of demand for air travel, the government said that even without a new runway at Heathrow, UK airports would serve 445 million passengers per annum (mppa) in 2050. This is more than twice the 211 mppa served in 2010.

The Department for Transport (DfT) said UK aviation emissions, including international flights departing from UK airports, would reach 47MtCO2e by 2050 without airport expansion. With new runways, passenger numbers could rise to 480mppa, the DfT says. Carbon Brief estimates this would translate into emissions of 51MtCO2e in 2050.

This figure is more than two-thirds (71%) of the 72MtCO2e mid-range carbon budget for 2050 implied by the CCC (Committee on Climate Change, the government’s official advisers), if the UK is to play its part in meeting the ambition of the Paris agreement. It is also nearly a third (32%) of the budget for 2C, assuming the UK sticks with its 80% by 2050 target.

This is a reminder of just how long we have been waiting for this decision:

Greenpeace has reiterated that it will, with local councils around Heathrow, take legal action if a third runway at the UK’s biggest airport is given the go-ahead.

Executive director John Sauven said:

Is the May government about to repeat the error of the Brown government and assume both the laws of nature and the law of the land can be fudged to allow another runway? That was the mistake Gordon Brown made shortly before the High Court blocked his Heathrow plan. We stand ready, with four Conservative local authorities, including Theresa May’s own council, to bring a judicial review against a green light for a third runway.

In Harmondsworth, one of a handful of villages set to be partly or wholly demolished if Heathrow expands, residents and campaigners began gathering early in the Five Bells pub, on the village green.

Emma Steele, who lives a few doors down, opposite where the new runway is scheduled to be built, said she was “not shocked, but definitely angry” at the widespread assumption that Heathrow will be chosen.

I elected David Cameron because he promised no third runway, and then it all gets U-turned around. I’m shocked Theresa May can let us down like this.

The prospect of the loss of the village, she said, “almost makes you speechless. It’s apocalyptic.”

On the small village green, campaigners were hammering banners showing politicians, including May, voicing their opposition to Heathrow expansion in the past.

Christine Frangleton, the pub’s manager, said she had been told it would just escape demolition, along with the Norman church of St Mary’s (on left of picture above) and a grade I listed medieval barn, but they were not convinced.

Even if it were allowed to stand, however, “You couldn’t possibly run a business when the runway is just over there. You couldn’t even live here,” she said.

“I’m not shocked, but what most people are disappointed with is the delay. We are so tired of it.”

John Allan, chairman of London First, told BBC Radio Four’s Today programme:

From a UK perspective Heathrow is probably the right answer, but the critical thing is that they make a decision.

What we want above all is more airport capacity in the south east. The most important thing is to get on with it. Even though it is only a step in the road, it is a very important step in the road.

Here is a potted history of Heathrow:

Jeremy Taylor, from Gatwick Diamond Business, told the BBC it is “disappointing” that Heathrow is the frontrunner. He also said that a third runway at the capital’s largest airport is unviable, partly because of the level of opposition to it, and a decision in favour of expansion there would just be “delaying the day when we see a second runway coming to Gatwick”.

Daniel Moylan, a consultant for Gatwick Airport, described the Heathrow expansion option as “rubbish” when he was aviation advisor to then-mayor of London Boris Johnson.

He ttold BBC Radio Four’s Today programme

Well, I’ve always thought that Heathrow is a rubbish idea, going back the last 15 years.

The pattern of history we see here is that there’s a group of people who keep batting for another runway at Heathrow. They keep coming forward with proposals, they always fail. And instead of learning their lessons, they have another go at the brick wall.

One of the cabinet members opposed to Heathrow expansion has arrived at Downing Street.

Greening’s constituency of Putney, Roehampton and Southfields stands to be adversely affected in terms of aircraft noise by an expanded Heathrow.

A survey of 647 UK exporters found that only 35% were happy with current provision at their local airport.

Just over a third (37%) believe extra international routes at their local airport would help them sell more goods and services overseas and the figure rises to 43% among exporting businesses in London.

Lloyds Bank Commercial Banking, which carried out the research, says the results underline “the importance of the decision about a new runway in the south east”.

Geoffrey Spence, head of infrastructure, resources and energy at Lloyds Bank Commercial Banking, said:

Our survey demonstrates that connectivity is an issue right across the UK and not simply in and around the capital.

There are many factors at play when it comes to British businesses reaching the government’s ambitious export targets, but being able to quickly and easily access key overseas markets is clearly one of the most important.

Companies across Britain will hope that the decision over expanding capacity in the South East marks the beginning of investment to ensure the UK and its airports are not left behind by rival exporting economies.

The co-leaders of the Green party, which opposes expansion at both Heathrow and Gatwick, have warned of the environment impact of today’s decision.

Caroline Lucas said:

The government is on the brink of announcing climate-wrecking plans for airport expansion in south east England. We know that that laying more tarmac at either Heathrow or Gatwick will bust any hope we have of meeting our climate change commitments, and inflict noise and air pollution on already blighted local communities.

Instead of expanding these airports the government should introduce a frequent flyer levy to reduce the need for any new runway capacity and invest the money raised in further measures to offer climate-friendly alternatives to air travel. I urge ministers to look at this proposal – and hope that opposition parties can join together in opposing airport expansion and backing this sensible alternative.

Jonathan Bartley, condemned Labour’s reported likely backing for a third runway at Heathrow.

He said:

The Labour party appears to have fallen into line with the government on airport expansion. Despite longstanding opposition to such a move from Jeremy Corbyn and John McDonnnell it seems that the party may swing behind further expansion of the busiest airport in Europe.

Such a cross party consensus on airport expansion is deeply disappointing.

One of the arguments against a third runway at Heathrow is that the already stretched transport infrastructure in the area could not cope.

There’s a timely reminder of the congestion that already often blights the area this morning.

I’m now handing over the live blog reins to Haroon Siddique, who’ll cover the Heathrow announcement – whenever it comes – plus all the day’s other politics news.

Environmental activists, communities and local authorities are preparing for a campaign of opposition to a third runway at Heathrow, ahead of the decision.

Residents of villages threatened by the expansion have already been taking part in training for direct action, activists said, while four local councils have amassed a £200,000 war chest to fight expansion through the courts.

None will feel the impact of Heathrow expansion more than the residents of villages set to be partly or wholly razed to make way for a third runway. About 800 homes will be demolished, and thousands more will be made uninhabitable, campaigners say.

One of the villages under threat, Harmondsworth, has been home to Neil Keveren’s family for generations. His home will be 54 paces from the new boundary fence.

“I’ll be looking at it out of my kitchen window, and all the houses opposite me, and the ones close beside – and beside that and beside that – will be destroyed,” the 55-year-old said.

The Sun reports today that Theresa May’s own website did, once upon a time, carry a number of posts railing against the possibility of a third runway at Heathrow.

The posts, it says, were removed in 2013.

The MP for Maidenhead – a town that would be directly affected by any increase in flights to and from one of the world’s busiest airports – had commented in January 2009, when the then Labour government was mooting the plan:

A third runway will result in thousands of additional flights, increased noise and more pollution for thousands of people.

The website also quoted May in the Commons telling then transport secretary Geoff Hoon:

I hope that the secretary of state recognises that as a result of today’s announcement, nobody will take this government seriously on the environment again.

The Telegraph – which might not have Boris Johnson as a columnist any more but knows a thing or two about his thoughts nonetheless – says the foreign secretary is poised to open a rift within the cabinet as soon as any plan to expand Heathrow is announced:

Mr Johnson, the foreign secretary, is expected to make a statement shortly after in which he will argue that the decision is “wrong” and a “mistake”.

He will say that while he is a supporter of a “global Britain” after Brexit, an additional runway at Heathrow will increase pollution and noise levels.

Johnson, on his return to parliament as MP for Uxbridge and Ruislip South in 2015, made a bold claim in his acceptance speech (it was 4.30am, mind):

I will lie down with you in front of those bulldozers and stop the building, stop the construction of that third runway.

Later that year, he said he probably wouldn’t need to go that far:

I don’t think my services as a bulldozer blocker will be required for decades, if ever, because I don’t think it’s going to happen … It won’t succeed.

Theresa May has said that cabinet members with a longstanding opposition to Heathrow expansion – which would also include education secretary Justine Greening, whose constituency is Putney – will be allowed to speak out against any proposal to build or extend a runway.

The government is finally expected to announce its decision as to which London airport expansion scheme it will choose today.

The options are:

• building a third runway at Heathrow;
• extending an existing runway at Heathrow; or
• building a second runway at Gatwick.

The decision is due to be taken by Theresa May and other senior ministers at the airport subcommittee before cabinet this morning and the transport secretary, Chris Grayling, will make a statement to the Commons at 12.30pm. But it is possible news of the decision could come earlier – possibly before the markets open – because of its financial sensitivity.

Whichever path is chosen, it will have far-reaching implications, not just for the two airports but also for the residents surrounding them. People living close to whichever airport is chosen for expansion will face increased noise, pollution and traffic, and – in some cases – their homes being demolished.

Despite David Cameron’s infamous “no ifs, no buts” guarantee that there would not be a third runway at the capital’s biggest airport, Heathrow is considered the favourite, after the Davis Commission came out in favour of building a third runway at the west London hub more than a year ago.

But whatever happens today, it is unlikely to be the end of the matter.

Gatwick has said that even if Heathrow gets the green light it will remain on standby to deliver its own plan, as it believes that legal and political challenges will halt the west London hub’s expansion once again.

Greenpeace says it has joined forces with councils surrounding Heathrow – Hillingdon, Richmond, Wandsworth and Windsor and Maidenhead – to instruct lawyers to seek a judicial review over the environmental impacts of a decision to go ahead.

There will also be political repercussions. Zac Goldsmith, Conservative MP for Richmond Park and North Kingston, has promised to trigger a byelection if Heathrow is selected and would be likely to stand again as an independent with the support of his local party. It is possible he will resign today if Heathrow is chosen or wait until after a formal Commons vote on the issue.

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