More than a dozen MPs who were called into the prime minister's office in the final minutes of the Brexit debate on Tuesday believed they had received assurances the government would discuss clause C of an amendment tabled by the former attorney general Dominic Grieve.
Ms Allen insisted that the referendum was a binary vote and it didn't say that MPs should neglect their duty, but Nick hit back: "Your duty, some would argue, is to deliver Brexit, which is what the people have told you to do".
Sarah Wollaston, a prominent Tory Remain rebel, has indicated that she will accept this pledge from the Government, and will therefore not be voting against her party.
But government officials admitted that the concession does constrain their freedom in the Brexit talks.
The rebels said on Tuesday they were told the promise made by the prime minister was "a matter of trust".
The statement said: "We have not, and will not, agree to the House of Commons binding the government's hands in the negotiations".
The government last night gave into rebel demands to hand MPs an effective veto on May's Brexit deal.
Ramos Kicks Against Real Madrid Signing De Gea
It personally didn't affect me much but obviously I have people close to me that are affected by this more than me. I always said that it was a lie and yet people continued saying that I should not go to the national team.
The Prime Minister made a bid to break the deadlock on Thursday with a proposal for a temporary customs union arrangement between the whole of the United Kingdom and the EU.
Asked what concessions he had been given by the PM, Mr Grieve said: "The Prime Minister agreed that the amendments we had tabled, and the issue that we had raised about Parliament's role in the event of no deal, was an important one and undertook to work with us to put together amendments to present in the Lords which would address those concerns". "We have to come back together and we have to do the right thing".
The bloc's Brexit negotiators have published an analysis of the Prime Minister's plans which suggests strongly that they will not be accepted.
Meanwhile, the remain-supporting Conservatives are increasingly divided over whether to follow a similar path, although the threat of rebellion from a minority contingent of Brexit-supporting MPs within the party has so-far prevented government from making an overt commitment to a change of policy.
"In all conscience, I can not support the Government's decision to oppose this amendment because doing so breaches such fundamental principles of human rights and Parliamentary sovereignty".
"If she has given too much away I think there will be real anger towards her".
There are mutterings from Brexiteers that a betrayal on this could be the moment they go over the top and withdraw their support from the prime minister; this is a showdown averted but not killed off.