Having secured a revised Brexit accord with the EU – against the odds in the eyes of many – Boris Johnson faces a second race against time with his battle to secure parliamentary support at home for the deal.

The British prime minister returned to London from Brussels in the early hours of Friday morning to begin wooing sceptical MPs at Westminster ahead of Saturday’s momentous vote in the House of Commons.

Johnson’s government already has no majority in the House of Commons, and opposition to the deal from its unionist allies in Northern Ireland makes his task harder.

The Democratic Unionist Party (DUP), whose 10 lawmakers at Westminster have propped up the Conservative government, believes the agreement threatens Northern Ireland’s economy and “undermine the integrity of the (UK) Union”.

Charm offensive

The prime minister is expected to focus his attention partly on winning over Conservative Eurosceptics. Several have indicated they are likely to back the deal.

Jacob-Rees Mogg – ex-leader of the pro-Brexit European Research Group (ERG) and now Leader of the House of Commons – called on his colleagues to support the deal in an article for BrexitCentral.

“Not only has the Prime Minister been successful in negotiating a new Brexit deal when so many believed he could not, but he has achieved changes which are not merely cosmetic but fundamental,” he says.

The government may also secure some backing from more than 20 former Tory rebels, who were expelled from the party last month after defying the government over its Brexit strategy. They were overwhelmingly opposed to a no-deal exit from the EU.

Some want a second referendum, but it’s thought most may be more inclined to back Johnson now, albeit reluctantly.

Read more:

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Labour support?

The government is also likely to need the support of a number of opposition Labour MPs. The party leadership opposes Johnson’s new deal and has instructed Labour MPs to vote against it.

But some have already backed the government in previous votes, and several represent Leave-voting constituencies. Significantly, the leadership has not threatened those considering supporting the deal with any punishment.

Labour argues the new Brexit deal will damage the British economy, and threaten jobs and workers’ rights. Shadow Chancellor (finance minister) John McDonnell tweeted that Johnson had “sold out virtually every sector of our economy”.

The government will get no support from the likes of the Liberal Democrats, the Greens’ one MP, the Welsh nationalists from Plaid Cymru, or the Scottish National Party. But the SNP leader, Scotland’s First Minister Nicola Sturgeon, wrote on Twitter that she was afraid that Labour “would be quite happy to see this deal go through”.

Historic session

The weekend’s parliamentary session will be the first time the House of Commons has met on a Saturday since Argentina invaded the Falklands Islands in 1982.

It promises to be one of the most dramatic in decades, with the vote perhaps setting the country’s direction for years to come.

If the deal is passed at Westminster, the race will be on to pass the necessary legislation and ratify the accord ahead of the Halloween deadline. If it fails, more turmoil and uncertainty beckons in the days ahead.

UK law in the shape of the Benn Act compels the prime minister to seek another Brexit extension from the EU – something Johnson has repeatedly said he will not do.

Many people in the country – and in the EU – are struck by Brexit fatigue. Some MPs may be tempted to heed Johnson’s calls to “get Brexit done”.

But his critics say his message peddles a dangerous myth. Opponents of the new deal will feel temporary uncertainty is worth suffering to avoid what they believe would be highly damaging long-term consequences.

View the analysis of Euronews' UK correspondent Vincent McAviney in the video player above.