Theresa May has held crisis talks with potential Tory defectors as she launched a bid to stave off further resignations from her party.

The prime minister met former ministers Phillip Lee and Justine Greening separately as she tried to avoid a further walkout of Conservative MPs furious at her handling of Brexit.

It comes after three pro-EU Tories – Anna Soubry, Sarah Wollaston and Heidi Allen – quit the party on Wednesday to join the new Independent Group.

The Independent can reveal that Ms May initially refused to meet with pro-EU Conservatives but backed down after Mr Lee wrote her a scathing letter warning that more MPs could quit the party if she continues to ignore “pragmatic arguments” and instead “pander to a faction”.

The former justice minister and several other supporters of a fresh Brexit referendum in the “Right to Vote” group had requested a meeting with Ms May last week but she refused, saying her opposition to another poll ”has not changed” and suggesting they instead meet with Stephen Barclay, the Brexit secretary.

But writing after the three Tory MPs resigned, Mr Lee told the prime minister: “We backed your leadership bid in 2016 because we saw you as the best candidate to unite the party and country and we want you to succeed in doing so.

“However, your Brexit deal, which we know was hard-fought, has united Leavers and Remainers in the country against it.

“Your refusal to meet us to discuss a way forward is, therefore, deeply shocking. You have rightly berated Jeremy Corbyn for his refusal to engage seriously in a discussion about the future of the country.”

In a damning assessment of Ms May’s leadership, he accused her of putting “the long Conservative tradition of pragmatism, common sense and sound economic management ... at serious risk” and said her government had “alienated a swathe of the electorate – particularly the younger, socially liberal voters we have worked so hard since 2005 to persuade we were not indeed ‘the nasty party’”.

And warning that more Tory MPs could quit unless she takes notice, he said: “We have seen this week in the Labour Party the shattering consequences for a leadership which closes its mind to pragmatic arguments in the centre and instead panders to a faction.

“Against this background, your refusal to meet not only entrenches divisions in the Conservative family, but more importantly is not in the national interest.”

Ms May responded by inviting Mr Lee to a meeting the following day. After the discussions, a Right to Vote spokesperson said: “Talks were open and we are encouraged she listened to our case.” Mr Lee said he would be staying in the Conservative Party.

Which MPs defected to form Change UK? Show all 12 1 /12 Which MPs defected to form Change UK? Which MPs defected to form Change UK? Change UK Details on the individual MPs are in the following photos Reuters Which MPs defected to form Change UK? Heidi Allen Anti-Brexit MP for South Cambridgeshire resigned from the Conservative party on February 20 PA Which MPs defected to form Change UK? Chuka Umunna MP for Streatham since 2010 and prominent People's Vote supporter PA Which MPs defected to form Change UK? Anna Soubry The prominent anti-Brexit MP for Broxtowe resigned from the Conservative party on February 20 PA Which MPs defected to form Change UK? Luciana Berger MP for Liverpool Wavertree since 2010, resigned from the Labour Party over bullying and anti-semitism PA Which MPs defected to form Change UK? Sarah Wollaston Anti-Brexit MP for Totnes resigned from the Conservative party on February 20 PA Which MPs defected to form Change UK? Joan Ryan MP for Enfield North resigned from the Labour party on February 19 citing its tolerance of a "culture of anti-Jewish racism" PA Which MPs defected to form Change UK? Ann Coffey MP for Stockport since 1992 Chris McAndrew / UK Parliament Which MPs defected to form Change UK? Gavin Shuker MP for Luton South since 2010 Getty Which MPs defected to form Change UK? Chris Leslie MP for Nottingham East since 2010 PA Which MPs defected to form Change UK? Mike Gapes MP for Ilford South since 1992 PA Which MPs defected to form Change UK? Angela Smith MP for Penistone and Stocksbridge since 2010

The prime minister also responded to the joint resignation letter from Ms Soubry, Ms Wollaston and Ms Allen to insist that her government shows the Tories “are the moderate, open-hearted Conservative Party in the One Nation tradition that you speak of”.

She said she was “determined that under my leadership the Conservative Party will always offer the decent, moderate and patriotic politics that the people of this country deserve”.

As speculation about further resignations swirled around Westminster, one of those tipped to be on the verge of quitting, former education secretary Justine Greening, admitted she would not be able to stay in the party if there was a no-deal Brexit.

Speaking hours before meeting Ms May in Downing Street, she told BBC Radio 4’s Today: “It is something that I have considered, but I have reached a different conclusion for the moment.

“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.”

'Anti-EU squad that have destroyed every leader for 40 years now running the Conservative Party,' says Anna Soubry

Dominic Grieve, the former attorney general, also said he would resign if the government pursues a no-deal Brexit.

He told the BBC: “The government which I am supporting implementing a no-deal Brexit – what would I do?

“I would not be able to maintain my support of the government. I would have to leave the party.”

Ms Wollaston told Today that up to a third of the cabinet could walk out if Ms May allows the UK to leave the EU without an agreement.

She said: “I know that there are many colleagues on my side who will be watching carefully and expecting Theresa May to be certain that she is not going to take us out on a no-deal Brexit.