Activists have occupied Tate Modern’s Turbine Hall with the aim of giving an all-night performance criticising BP’s sponsorship of the gallery.

The group intend to cover the hall’s 152-metre sloping floor, which once housed the oil-fired turbines of the Bankside power station, with thousands of charcoaled words of warning about climate change.

The performers said the art work would take 25 hours to complete, if they manage to remain inside the building, and is timed to coincide with a full tide cycle.

Eva Blackwell, of the arts activism group Liberate Tate, said the protest was “a textual intervention”.

“We’re filling the Turbine Hall with a tide of ideas and narratives of art, activism, climate change and oil,” she said.

The words were sourced from a range of books and reports, including Margaret Atwood’s dystopian novel Oryx and Crake, the UN’s latest climate science report and Naomi Klein’s This Changes Everything: Capitalism vs the Climate.

The Tate has tolerated the group’s performances in the past, including a naked man being doused in oil at Tate Britain, extracts from the court case against BP’s Gulf of Mexico oil spill whispered throughout their galleries and a public exorcism of the “evil spirit of BP”. There have been 14 events in all.

The Turbine Hall performance, however, is the first to defy the gallery’s opening hours, and a showdown with the Tate’s security team is likely before it closes at 10pm.

Protester Yasmin de Silva said the group was compelled to adopt a more antagonistic attitude by the looming climate talks in Paris in December.

“Oil companies like BP are trying to carry on pretending its business as usual, but time is running out to act on climate change. We’re already seeing the impact of climate change globally, and companies, foundations and institutions around the world are turning away from the fossil fuel industry that’s driving us to climate disaster,” she said.

The group began protesting against the Tate’s links with BP in 2010. In January, after a three-year legal battle over a freedom of information request, it was forced to reveal the extent of BP’s support, which amounts to an average of £224,000 a year.

The gallery has described BP’s contribution as considerable, but according to campaigners from Platform, which made the FOI request, it represents just 0.3% of the Tate’s 2013-14 operating budget. They have described the sum as “tiny” and questioned why the Tate has clung so hard to the funding.

Elisabeth Monro, a Tate visitor who used to work in art sponsorship, said the performance was “as valid an installation art piece as anything else here. The whole reason to have modern art is to have dialogue.”

She said she did not necessarily agree with the protesters’ call for the Tate to drop BP’s money, but that it was a “surprisingly low” amount.

“We all benefit from corporate sponsorship of the arts. Without corporate sponsorship we wouldn’t have buildings like this, because the government doesn’t give enough,” she said. “I think it’s very difficult where you draw the line about which company is acceptable.”

Glen Tarman, a member of the Liberate Tate movement since its inception, said: “Art museums are places where we make sense of the world. We make meaning from our lives and they contain what we most value. We shouldn’t be complicit in climate change just because we appreciate great art.”

He said the group was increasing its calls for the Tate to drop BP’s sponsorship because the deal was due to expire in 2016. He said the growing divestment movement, which has seen the Rockefeller Foundation, the Church of England and dozens of universities drop fossil fuel investments, was an example of the mounting view that public institutions should not be tied to the companies that drive climate change.

“We wanted to do a performance that confronted them more fully. This year public institutions are breaking links with fossil fuels every week. This work is about calling on the Tate to make their decision [about whether to renew their contract with BP] earlier, preferably by the Paris climate talks in December.”

Many visitors to the Tate Modern were initially unaware that the performance was unsanctioned. Frances O’Neill, an artist, said she had viewed the work from the balcony above and, without knowing it was a protest was nonetheless “really, really moved”.

“I was just mesmerised by the visuals of it. I didn’t know what they were writing, I just got filled with a deep sadness,” she said. Once she read the interpretation signs laid out by the group she said she was supportive of the action.

“Someone’s got to do these sort of things. Someone’s got to say our planet’s being damaged. It may not be sponsored [by the Tate], but they are doing what the Tate does,” she said.

Another visitor, Audrey Valentine, said she thought it was wonderful the Tate was allowing the protest to unfold, but she that she did not agree with its message. “If these big boys didn’t do these things, are you suggesting that government should pay? They should put some money back,” she said.

Liberate Tate’s campaign against the Tate’s relationship with BP is part of a wider drive to rid the art world of oil patronage. The British Museum, National Portrait Gallery and National Theatre are among many major UK cultural institutions that receive support from fossil fuel companies.