Brussels – Britain and the European Union reached a new divorce deal Thursday that could allow Brexit on October 31, but faced immediate opposition among MPs in London – who could still block it.

The deal was sealed just hours before a summit of EU leaders that is expected to endorse the text, but it must pass the British parliament when it meets on Saturday.

British Prime Minister Boris Johnson, who has staked his premiership on leaving the EU at the end of this month, said he had secured a “great new deal that takes back control”.

European Commission chief Jean-Claude Juncker said: “It’s a fair and balanced agreement for the EU and the UK and it is testament to our commitment to find solutions.”

The deal is a victory for Johnson, who took office in July promising to end Britain’s membership out of the European bloc in line with the result of a 2016 referendum.

He vowed to renegotiate a previous text that MPs rejected three times, or take Britain out of the EU with no deal on October 31.

But it could quickly turn to defeat if the House of Commons refuses to endorse the deal when it meets for a special sitting on Saturday – and the omens are not good.

The pound surged on news of the deal before losing ground over doubts that parliament will approve it.

The Northern Irish party on whom Johnson’s Conservatives depend in parliament, the Democratic Unionist Party (DUP), said it “will be unable to support these proposals”.

“These arrangements would not be in Northern Ireland’s long term interests,” it said.

Britain’s main opposition Labour leader, Jeremy Corbyn, also urged MPs to reject it.

“The deal he’s proposed is heading Britain in the direction of a deregulated society and a sell-off of national assets to American corporations,” Corbyn told British broadcasters.

The draft agreement was forged just weeks before Britain was due to leave the bloc, ending more than four decades of close economic and political ties with its nearest neighbours.

Weeks of tense negotiations focused on changing the arrangements to keep open the border between British Northern Ireland and EU member Ireland.

Chief EU negotiator Michel Barnier said: “We have managed to find solutions that fully respect the integrity of the single market.

“We created a new and legally operative solution to avoid a hard border, and protect peace and stability on the island of Ireland.”

But the DUP made clear it had concerns about the arrangements for giving a say to devolved authorities in Belfast, as well as the plan to see Northern Ireland remain under EU customs and Value Added Tax (VAT) rules.

Johnson reassured Juncker he could get the deal through parliament, when the two men spoke on the telephone earlier Thursday, Barnier said.

French President Emmanuel Macron told a meeting of centrist leaders in Brussels that he was “reasonably confident it can be ratified by a vote of the British parliament”.

Responding in English to a British journalist, he added: “I’m not your prime minister. This is [up to] your prime minister to deliver now a vote at your parliament.” AFP