A senior City figure who was a remain supporter during the EU referendum has urged Theresa May to “get cracking” with the Brexit process, warning that any delays would only cause more uncertainty for business.

John Nelson, the chairman of Lloyds of London, said: “To be blunt with you, the longer the uncertainty goes on the worse it is for business.”

His intervention, while travelling to India as part of a delegation accompanying the prime minister, is significant because he has been a vocal opponent of hard Brexit.

But while some pro-EU campaigners want to push back the triggering of article 50, Nelson said delays could be damaging.

“I think unfortunately if it means greater uncertainty for a longer and longer period it is not so good,” he told the Evening Standard. “Get cracking is my view. It’s not a view that’s shared by all my colleagues here.”

Lloyds announced major expansion plans during May’s three-day visit to India, designed to boost economic ties between the two countries.

Nelson said he believed ministers understood the importance to City-based firms of resisting non-tariff barriers in the deal negotiated with the EU.

“From our point of view we are very, very keen to have passporting rights and single market access,” he said. “I detect that ministers are getting that very strongly now indeed.”

He said it was important to prevent a cliff edge: “The other thing is we have to negotiate transitional arrangements otherwise we will be at a cliff edge for both sides, the EU and us. And they won’t start negotiating those until article 50 has been moved.”

May addressed Brexit during the last day of her trip to India in Bengaluru, also known as Bangalore, during which she visited a temple dressed in a sari.

She met schoolchildren while watching an Indian air force fly-past – offered for the first time to a visiting head of government in the city.

The prime minister also visited the Dynamatic Technologies facility where Airbus took delivery of the first set of A330 wing components, produced jointly in the UK and India.

The visit, which had earlier involved bilateral talks with the Indian prime minister, Narendra Modi, in Delhi, was designed to lay the groundwork for a trade arrangement with India post-Brexit.

In an interview with Sky News, May was asked if she felt the Vote Leave campaign had been dishonest. “I think what we need to do now is not focus on what happened during the campaign,” she said.

“People voted on whether or not they wanted to leave the EU. They voted to leave the EU and what I’m focusing on now and what I’m determined to do is to deliver on that and make a success of it.”

She refused to say if she would go for a transitional deal after 2019 under which the UK might maintain access to the single market by paying into the EU budget.
“All I’m focusing on is preparing to trigger article 50 and then we will be in those formal negotiations,” she said.

The comments came amid a suggestion in the FT that May could announce details of her Brexit plans for financial services and other key sectors within weeks in a bid to reassure business leaders and MPs.

Some have accused May of failing to have a plan for Britain’s EU exit, although she has insisted that giving a running commentary could harm the country’s negotiating position.

The question of article 50 has caused controversy ever since three high court judges ruled that May could not start the formal process of leaving the EU without a vote in parliament.

No 10 is appealing to the supreme court in the hope of overturning the decision amid worries that pro-EU politicians will seek to delay or block plans by amending legislation.