Brussels recognised the need to time-limit the Irish border backstop before officials took negotiations in "another direction", a former Brexit secretary has suggested.
Conservative MP Dominic Raab said Michel Barnier, the European Union's chief negotiator, told him he understood the backstop "needs to be short" after being challenged over making it finite.
Mr Raab added he made clear to Prime Minister Theresa May that the UK should have "stood firm", adding a "robust" line should now be taken given the room for movement on the issue.
He went on to describe the Brexit deal as the "worst of all the alternatives" and said some of the no-deal Brexit warnings issued by the Government are "just not credible".
Mr Raab, who quit the Cabinet last month over the Brexit deal, also suggested Work and Pensions Secretary Amber Rudd's suggestion that men at Westminster "seem to flounce out quite a lot" sounded "a bit sexist".
Speaking to Sophy Ridge On Sunday on Sky News, Mr Raab said he suspects the deal will be voted down but could still be "remedied" if the EU is willing to look again at the backstop and that the UK will transition to a free trade agreement.
After saying there were moments the UK could have "pressed harder" on the backstop during the talks, Mr Raab added: "You could see this backstop issue coming down the line. It was obvious. It wasn't a shock or a surprise.
"I made clear that it had to be time-limited and finite, and Michel Barnier, at one point in one of our meetings, said 'I understand it needs to be short', but I'm afraid after that the technical track for the negotiations took it in another direction and I was very clear with the Prime Minister that we should of stood firm at that point, and that was back in July.
"Now I'm not suggesting it's easy to go back. You lose moments in negotiations and you can't just claw them back. What I am suggesting is that there is probably more flexibility than is being suggested and actually we should have taken a robust line back then and we certainly should be taking one now."
On no-deal technical notices issued by the Government, Mr Raab said: "Well I scrutinised all of those papers and frankly I can say, now as a backbencher, that some of those assumptions are just not credible."
Asked about Mrs May's future, Mr Raab added: "I think she could still, even in the event of a big loss on the vote, which we expect, I think she could still turn it round. But we need a change of approach. She needs to go back with a, if you like, a best final offer to the EU."
Mr Raab later said he would not rule himself out of running for leader but stressed he would not "get sucked into that debate".
When pressed about Ms Rudd's "flounce" comment, Mr Raab replied: "Amber does this every now and again.
"She did it during the referendum when she personalised an attack on Boris (Johnson).
"I'm not sure if that's aimed at me. It sounded frankly a bit sexist to me.
"The reality is, I stood up and tried to make it work. But I couldn't in good conscience go to Brussels and sign a deal with Michel Barnier that I feel would be so damaging to the British economy and devastating to our democracy."
