London (AFP)

Back in London after wringing a deal on Brexit from the European Union, Boris Johnson is engaged in a charm offensive to sell it to very recalcitrant MPs before a historic vote in Parliament on Saturday.

Deciding to leave his country of the EU on October 31, the British Prime Minister said he was "confident" that this "very good agreement" would be approved during a special session in Westminster, the first to be held on a Saturday since the Falklands war 37 years ago.

The task looks daunting and the leader will have to fight for each vote, as the vote promises to be tight. He made phone calls to MPs on Thursday, according to Downing Street, and must continue his persuasion business on Friday.

The Conservative government now has only 288 elected members, compared to an absolute majority of 320 in the House of Commons, where former Prime Minister Theresa May failed three times to pass her divorce agreement before 'sponge.

Opposition parties have already warned that they will vote against the agreement, with Labor arguing that it threatens to undermine workers' rights and environmental standards after Brexit.

In particular, the Northern Ireland Unionist Party DUP, a key ally of the Westminster executive, is up against the compromise, which in its view shatters the integrity of the United Kingdom by providing for a different treatment for Northern Ireland.

No question of moving, insisted Friday Sammy Wilson, the DUP deputy responsible for Brexit, on the BBC: "I can give you the absolute assurance that we will not vote for this agreement".

The DUP has only 10 elected in the Commons but the green light would have convinced the few dozen "Brexiters" the hardest of the Conservative Party, whose position remains unknown.

- "Dumb" -

It's a win, win, win deal for the UK because "we are taking back control of our laws, our borders, our money," defended Foreign Minister Dominic Raab on the BBC. "Those who want to criticize or block this deal want to keep the UK back."

In the line of sight of Boris Johnson, Brexiters pure juice and Labor MPs representing constituencies in favor of "Leave".

The British press was generally behind him on Friday. "Be realistic, take the deal," headlines the eurosceptic tabloid The Sun while the Times believes it would be "stupid" for the Brexiters to reject the deal.

"It's a bad deal but if I thought there would be no Brexit at all, I would consider voting for," admitted Labor Graham Stringer on the BBC.

Labor chief John McDonnell warned that there would be "consequences", without further details, for those who defied the party's vote.

A failure of Boris Johnson in Parliament would prolong the great uncertainty in which the United Kingdom is plunged since the approval of Brexit by referendum in June 2016.

A law passed in September by the opposition, with the support of 21 Tories rebels, forced him to ask Brussels a new three-month postponement of Brexit. This would require the unanimous endorsement of the 27 EU Member States.

Coming to power on the promise to take the UK out of the EU at all costs on October 31, Boris Johnson categorically excludes Brexit, already postponed twice, without saying how he would do it.

"The Prime Minister's position is the new agreement, disagree, but no postponement," said a British official.

For the opposition, the best solution would be to consult the British again by referendum.

The aim is to avoid the return of a physical border between British Northern Ireland and the Republic of Ireland, which will remain a member of the EU, to preserve peace after decades of violence.

More generally, the text provides for the conditions for divorce between the United Kingdom and the EU after 46 years of life together, in particular as regards citizens' rights and compliance with financial commitments. It introduces a transition period until December 2020.

© 2019 AFP