THERESA May has called in leading Remainer Tories to Downing St to try to stem the flow of defections to the anti-Brexit Independent Group after senior ministers hinted they might resign if there were a no-deal outcome.

The Prime Minister also wrote an emollient letter to her three former Conservative colleagues – Anna Soubry, Sarah Wollaston and Heidi Allen – who this week resigned to join the new Westminster group dubbed TIG, saying while she respected their decision, she did “not accept the picture you paint of our party”.

In a clear signal that she might be prepared to leave the Tory Party, and possibly join her fellow Remainers in TIG, Justine Greening, the former Education Secretary, was asked if she could stay a Conservative if the Government led the country into a no-deal Brexit.

"I don't think I would be able to stay part of a party that was simply a Brexit party that had crashed us out of the European Union," declared the Putney MP.

Her comments followed those of her fellow Tory Remainer Dominic Grieve, the former Attorney General, who had earlier suggested he could not stay in the Conservative Party if there were a “catastrophic” no-deal.

Ms Greening, pointing out how she had "not seen the Prime Minister recently" despite asking "on multiple occasions," made clear the Tories could not be successful in the long term if they were just a party of Brexit.

"If we are not a party that seems credible on economic policy or on opportunity; if we don't reach out to a new generation, then we have to accept that we will simply not have the level of support in the country we need to be a credible political party," she added.

Hours later, the former Secretary of State was in Downing St for talks with Mrs May as was another Tory Remainer Philip Lee, who last summer resigned as a Justice Minister over the Government’s Brexit approach.

On Monday, four Cabinet ministers – Amber Rudd, Greg Clark, David Mundell and David Gauke – had talks with the PM over their concerns about a no-deal. It was suggested that if Mrs May did not effectively rule one out, then they could resign and back an amendment, tabled by Labour’s Yvette Cooper, to put off such an outcome by extending the Article 50 process.

Following a speech in Edinburgh to mark 20 years of Scottish devolution, the Scottish Secretary, asked if he would resign his ministerial role in the event of a no-deal Brexit, said he would "do everything I can and whatever I deem necessary to prevent a no-deal Brexit coming about". He made clear, however, he would not be joining TIG.

After Dr Wollaston claimed a “third of the Cabinet” could resign in the face of a no-deal outcome, Philip Hammond was asked repeatedly if he would step down in such a scenario.

The Chancellor dodged the question, saying in response: “I have always said and I have been very clear and consistent about this, that no-deal would be an extremely bad outcome for this country and we must do everything possible to avert that outcome...”

Later, Downing St released a letter the PM had written to Mss Soubry, Wollaston and Allen in which she expressed sadness at their departure.

Mrs May rejected their claims the party had been taken over by the hard Right and that she had given up on her promises to deliver a fairer society.

"I know you will not have come to your decision lightly but I must say that I do not accept the picture you paint of our party," wrote the PM.

"Indeed, in each of the areas you highlight, our record in government shows that we are the moderate, open-hearted Conservative Party in the One Nation tradition you speak of."

Meanwhile, one of the 11 TIG MPs, former Labour backbencher Gavin Shuker suggested the new grouping, which has more members than the 10 Democratic Unionists, would be willing to prop up Mrs May’s Government in return for a promise to hold a second Brexit referendum.

The Luton MP suggested a confidence and supply agreement would be conditional on support for a second EU poll along the lines of the compromise plan set out by Labour’s Peter Kyle, which would see MPs back the Withdrawal Agreement but the public would then be given the final say in another referendum.