Dominic Grieve, the former attorney general who is leading the group of Remain-supporting Tory MPs, said today they were not trying to stop Brexit from happening - but added they could topple the Government by voting against the bill, to prevent the risk of Britain sliding into "chaos" by leaving the European Union with no deal in place.
Consequently, the Government has now changed its proposed amendment to the EU Withdrawal Bill again, so that, should MPs vote down a UK-EU Brexit deal, Theresa May announce before January 21st 2019 that no deal has been reached, or January 21st pass with no deal being struck, a Government minister will give a statement to Parliament which can be put to a "vote on neutral terms" - but with no opportunity to reject a "No Deal" exit and keep Britain in the EU.
The former Attorney General said: "We could collapse the government".
"The problem is that the Brexit process is inherently risky".
Buckland indicated the government would look into the possibility of adopting Grieve's push for ministers to secure parliamentary approval for their Brexit plans if they fail to negotiate a deal with the EU.
However, the amendment to the EU Withdrawal Bill tabled on Thursday leaves Parliament facing a "deal or no deal" choice.
May promised the would-be rebels the Government would put forward a new amendment to the EU Withdrawal Bill that would beef-up the so-called "meaningful vote" plan in exchange for their support.
"The alternative is that we have all got to sign up to a slavery clause now saying whatever the government does, when it comes to January, however potentially catastrophic it might be for my constituents, and my country, I'm signing in blood now that I will follow over the edge of the cliff. I hope they listen to me when I say I don't understand why you've done this last-minute switch", he added.
The government's prospects of defeat were increased last week when the junior justice minister Philip Lee resigned his post so he could vote against the minister on a meaningful vote. But the wording of the promised compromise has now been published.
Asked if voting against the Government could bring it down, Mr Grieve told BBC1's Sunday Politics: "We could collapse the Government".
"I think it is unacceptable because it seems to me to be contrary to what the whole intention was behind this whole amendment".
This gives the European Union very little incentive to negotiate constructively with Britain, knowing that it can stop Brexit by offering a bad deal, safe in the knowledge that MPs will not accept it or the alternative of a "No Deal" exit.
"I've had communications, conversations with ministers at all levels who are concerned about the direction of travel", he told the BBC.
Shortly before the text of the amendment was tabled, former minister Anna Soubry tweeted to say that "deal or no deal Parliament will have a meaningful vote and ... there will be no hard Brexit".
Crucially, the motion will be unamendable, meaning that MPs can not insert a requirement for Mrs May to go back to the negotiating table, extend the Brexit transition or revoke the UK's withdrawal under Article 50. Instead, MPs will be offered a vote on an unamendable statement, which would effectively turn any vote into to a vote of confidence in the prime minister.
"I did indeed meet a group of my fellow MPs", he told BBC One's Andrew Marr Show.