The Brexit Secretary predicted the negotiations will drag on until the last minute on the last day in 2019 and be “very exciting”.
Asked if that meant the promised Parliamentary vote on the agreement could be delayed until after Brexit Day, in March 2019, Mr Davis replied: “Yes, it could be”.
The threat blows out of the water the Prime Minister’s repeated pledge of a vote – although she insisted it would not allow Parliament to halt withdrawal.
A cross-party alliance of MPs is attempting to amend the Brexit Bill to require that vote to be a separate Act of Parliament, to give Parliament more muscle.
And a separate amendment aims to use it to prevent the UK crashing out of the EU with no deal, if the talks collapse.
The vote was expected at the end of next year – the EU’s deadline for agreement, to allow ratification – but Mr Davis ripped up that timetable, when giving evidence to a Commons committee.
Warning EU deals tended to be agreed at 11.59pm on the last day - or even later, by stopping the clock – he told MPs: “That’s exactly what I would expect to happen here”
And he added: “It will be very exciting for everyone watching.”
Asked where that left the Parliamentary vote, Mr Davis said it would not take place until afterwards – which could mean after the UK has left the EU, on March 30, 2019.
He said he hoped to agree a transitional deal in the “first quarter of next year” – if the UK passes the “sufficient progress” test on divorce terms in December.
But Theresa May has bowed to Brexiteer Tory MPs by insisting that deal will only be implemented if agreement on a long-term trading partnership has also been struck.
The claim that the nail biting talks will be “very exciting” is certain to anger business leaders who have demanded clarity on Brexit by the end of this year.
It also comes despite the Prime Minister refusing to confirm that the 3.2m EU citizens in this country will be able to legally stay, if the UK crashes out of the EU with no deal.
Earlier, Mr Davis acknowledged that major banks are threatening to move out of London to Frankfurt, Paris or Dublin if there is no deal “by March or April next year”.
He argued they would not incur that huge cost, if a transition deal looks likely, but admitted: “They might reduce the size of the office.”
Mr Davis also hinted that France – not Britain – would be to blame if there was no agreement and new customs arrangements were not in place.
Insisting the UK’s new customs systems would be ready for March 2019 regardless, he suggested the French were “not investing enough – which could cause “backlogs in the UK”.
The Brexit Secretary was also asked what questions the MPs should out to Michel Barnier, when he gives evidence to the Brexit committee in a fortnight’s time.
He suggested they find out what Mr Barnier means by the “sufficient progress” Britain must make to move the talks on to transition and trade – despite five rounds of face-to-face talks with him.
The EU has repeatedly made clear that Britain must move in three areas; the financial settlement, EU citizens’ right and the Irish border.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies