Conservative ex-cabinet minister Dominic Grieve has said he does not care about “knives being out for me” over his role in forcing changes to Theresa May’s Brexit plans, as he warned the Prime Minister she faces a second defeat.

The former-attorney general and ten other Tory MPs who drove the Government to give Parliament a greater say on EU withdrawal, faced a torrent of abuse overnight from eurosceptic fellow Conservatives and the Brexit-backing press.

But Mr Grieve said it is “not going to affect what I do one jot” as he signalled Conservative rebels are prepared to defy the Government again when it tries to bring forward plans to enshrine the date of Brexit in law next week.

He was backed by fellow Conservative Stephen Hammond, stripped of his senior party job after rebelling, who also would not rule out voting against the Government again.

They spoke after helping to inflict an embarrassing defeat on Ms May as she tried to push her EU Withdrawal Bill through the Commons, which led one eurosceptic Tory to brand Mr Grieve and other rebels “idiots” while another accused him of “treachery” and said they should all be deselected as MPs.

But making clear he would not be deterred from trying to improve the Prime Minister’s Brexit proposals, Mr Grieve said the Government would be defeated again unless it withdrew plans to enshrine the date of Britain's exit in law as March 29 2019 – something he and others claim will make crashing out of the EU with no deal more likely.

Brexit: the deciders Show all 8 1 /8 Brexit: the deciders Brexit: the deciders European Union's chief Brexit negotiator, Michel Barnier Getty Brexit: the deciders French President Emmanuel Macron Getty Brexit: the deciders German Chancellor Angela Merkel Reuters Brexit: the deciders Commission President Jean-Claude Juncker EPA Brexit: the deciders The European Parliament's chief Brexit negotiator Guy Verhofstadt Getty Brexit: the deciders Britain's Prime Minister Theresa May Getty Images Brexit: the deciders Britain's Chancellor of the Exchequer, Philip Hammond PA Brexit: the deciders After the first and second appointed Brexit secretaries resigned (David Davis and Dominic Raab respectively), Stephen Barclay is currently heading up the position PA

He said: “I hope very much it won't be necessary because if the Government comes back with that date, I'm sure the Government will be defeated and I have no desire to defeat the Government or be involved in the Government's defeat a second time.

“I've been in Parliament for 20 years and apart from HS2, I don't think I've ever rebelled before.”

He went on: “Not only am I open to negotiation, my whole life is negotiation.”

Mr Grieve appeared on BBC’s Newsnight hours after the vote, which followed angry clashes in and outside the Commons with eurosceptic fellow Tories.

Ms May arrived in Brussels for another crunch EU summit on Thursday, with the vote in Parliament raising questions as to whether she has the political authority to deliver any Brexit deal agreed on the continent.

But Mr Hammond, whose vote against Ms May saw him sacked from his job as vice-chair of the party, said the result would help create space for Parliament to properly scrutinise the eventual Brexit deal and to have a fair say on it.

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Asked whether he too might rebel on the plan to enshrine the Brexit date in law next week, he said: “I hope not.”

But he added: “There‘s a week to go, plenty of time for negotiation.

“I think many people will view that proposition as unnecessary, probably not a good way to negotiate.”

Conservative Nadine Dorries, who consistently rebelled against David Cameron’s administration as it tried to bring in equal marriage legislation, demanded her fellow Tory MPs be stripped of their seats in Parliament for “treachery” against the Prime Minister.

She tweeted that they had, “put a spring in Labour’s step, given them a taste of winning, guaranteed the party a weekend of bad press, undermined the PM and devalued her impact in Brussels.”

Tory Sir Desmond Swayne told the Commons the rebel amendments simply aimed to delay Brexit, dismissing them as “sanctimonious guff” and Mr Grieve and their other advocates as “idiots”.

He added: “Now we see the real motive and of course he was assisted by others, who comrade Lenin would have properly referred to as useful idiots.”

Senior Tory Bernard Jenkin said: “To dress this attempt to reverse Brexit as an argument in favour of parliamentary sovereignty is nothing but cant.”

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But Mr Grieve also said he would not be affected by criticism from fellow Tories, adding: “I'm not very concerned about knives being out for me.

“I'm in Parliament to do my duty by my constituents and by my country. Knives can be anywhere, I'm not going to be bothered by that in any way at all.”

He went on: “I'm sorry to hear if colleagues think so ill of me but it's not going to affect what I do one jot.”

Mr Grieve said he had been willing to discuss with the Government how to come to a compromise that would address the concerns he and others had over Brexit plans.

Desmond Swayne branded fellow Tories as 'idiots' for rebelling against Ms May's Brexit plans (House of Commons)

But he said: “I'm sorry that the negotiations foundered, it was a spectacular foundering, I can't deny that ... but there appears to have been a complete breakdown within Government as to how to answer perfectly legitimate points.

“It is slightly worrying but I've no doubt people will learn from the experience.”

Up to now Ms May had promised Parliament a say of sorts over the final deal she agrees in Brussels, but as it stood it would be a ‘take it or leave it’ vote and ministers would retain powers to enact any deal without first gaining Parliament’s permission.

The change forced by rebels, backed by Jeremy Corbyn’s Labour MPs, means the terms of any Brexit deal must now first be approved with a full Act of Parliament – effectively allowing MPs to re-write parts of the deal before any of it is implemented by Ms May.

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This morning Health Secretary Jeremy Hunt said the defeat would not derail the Brexit process.

He told BBC Radio 4's Today programme: “I don't think it should be a surprise that in a hung Parliament, Parliament wants to reassert its right to scrutinise the process.

“But we should also be clear this isn't going to slow down Brexit, it's not going to stop Brexit.

“When it comes to the unity of the Conservative Party, the big picture is not actually what happened last night but what happened last week, because people said it would be absolutely impossible for Theresa May to get a deal with Brussels that united the Cabinet and the party, and actually she got a fantastic agreement which met all our red lines and allowed us to move on to the next stage of the negotiations.”