Boris Johnson's 24 hours to save Brexit deal as support crashes

He has just 24 hours to convince enough MPs to support his alternative to the backstop.

A total of 635 votes will be in play when the deal is debated and Mr Johnson will need at least 318 to be a certain majority, the results of the ballot are expected at around 2.30pm on Saturday.

After a historic day in Brussels, the eyes of Europe are focused back on London for what is being teed up as a ‘Super Saturday’ in the House of Commons. Not since the Falklands War in 1982 has the UK Parliament been convened at the weekend.

Mr Johnson will issue MPs with a “my deal or no deal” ultimatum.

But a Remain alliance wants to make the deal conditional on a second referendum.

And DUP leader Arlene Foster accused the prime minister of being “quite desperate”, saying her party won’t back a border in the Irish Sea.

Despite the uncertainty, Taoiseach Leo Varadkar was being lauded in Brussels last night as the man who made the right compromises.

European Council President Donald Tusk said a deal “that was impossible yesterday” became possible because it had been “positively assessed by Ireland”.

Mr Tusk said the Brexit deal "allows us to avoid chaos and an atmosphere of conflict between the EU27 and the United Kingdom".

He didn't rule out a possible extension to the October 31 deadline for the UK's departure, but there is now a clear preference among EU leaders for Brexit to happen in just two weeks' time.

"Now we are all waiting for the votes in both parliaments," he said in reference to the House of Commons and European Parliament.

Having argued for months that the Withdrawal Agreement, including the Irish backstop, could not be reopened, the EU Council unanimously approved the new Irish protocol.

A visibly happy Angela Merkel told reporters that achieving the deal had been "real hard work".

The German chancellor called the agreement "a compromise for all sides" but noted it contains key demands from the EU side, including maintaining the integrity of the common market and preserving the Good Friday Agreement.

Leaders see Mr Varadkar's meeting with Boris Johnson outside Liverpool last week as the moment space was made for compromise.

The Taoiseach was invited to appear alongside Mr Tusk, the EU's chief negotiator Michel Barnier and EU Commission President Jean Claude Juncker as they briefed the international media.

Mr Varadkar said: "As the leader of a small nation, I have felt enormous solidarity from my European partners, and I think it's been demonstrated in the past few years it is a union of peoples and one in which small states are protected.

"I have mixed feelings today. I regret the UK is leaving but respect the decision to do so, like an old friend going on a journey without us, and we really hope it works out for them.

"There will always be a place at the table for them if they ever want to come back."

Irish officials accepted last night that the backstop had been scrapped after months of insistence that such a move would never happen. The new arrangement also includes a time limit which will see politicians in the North vote on their "special relationship" with the EU after four years.

Mr Varadkar said: "What we have is a revised agreement, a new solution, a unique solution which recognises the unique history of Northern Ireland, different from the backstop, more likely to be used to come into force and could become permanent, but only with the consent of the elected representatives of Northern Ireland."

Meanwhile Tanaiste Simon Coveney has said a no-deal Brexit is "very unlikely now" but added that predicting how tomorrow's crunch Westminster vote will go is "a dangerous game".

Mr Coveney also sought to reassure unionists that there is "no threat to the constitutional status of Northern Ireland under the deal".

Speaking on RTÉ Radio One this morning Mr Coveney said: "We don't think it's one-sided, that the democratic mechanism to maintain these arrangements in the future are on the basis of a simple majority.

"If you didn't have a simple majority endorsing the continuation of these arrangements for Northern Ireland you're essentially making the case that a minority of people in Northern Ireland should be determining the future for the majority."

Mr Coveney said the that there has been an attempt to design a "best of both worlds scenario" for Northern Ireland where trade can continue with both the UK and EU without tariffs.

He said this would be a "fantastic arrangement" for Northern Ireland.

Mr Coveney said of tomorrow's House of Commons vote: "I think it will be very close one way or another" and that it will have "enormous consequences".

He added: "Our job not to get involved in the politics of that or the party politics in Westminster. Our job is to negotiate the best deal possible from an Irish perspective, from an all-island perspective.

"That’s what we’ve done."

Mr Coveney said there will still be a focus on preparing for a no-deal "just in case".

"I think it's far less likely now but we have to continue to make sure that if a set of circumstances were to conspire to result in a no deal we have to be ready for that.

"But I think that is very unlikely now.

He said also said that if the deal doesn't get through Westminster and the choice is no-deal or an extension "the Irish government would strongly be advocating for an extension".

Mr Johnson appealed to those in the North as well as across party lines to encourage support for the deal.

"I am very confident that when my colleagues in parliament study this agreement that they will want to vote for it on Saturday and in succeeding days," he said.

"We've been at this now, as I say, for three-and-a-half years. It hasn't always been an easy experience for the UK. It's been long, it's been painful, it's been divisive.

"And now is the moment for us as a country to come together. Now is the moment for our parliamentarians to come together and get this thing done."

Brexiteers from the Conservative Party's European Research Group have come on board with the plan. Jacob Rees-Mogg, the leader of the house, urged MPs to back it.

But the DUP continues to claim it "drives a coach and horses" through the Good Friday Agreement. If Mr Johnson loses the vote, he will be obliged by law to write to Brussels asking for an extension to Article 50.