The U.K. and the E.U. have come to a new agreement on Brexit, just two weeks before Britain is scheduled to leave the European Union.
But whether Brexit will happen on Oct. 31 remains in doubt, as a crucial caucus of British lawmakers refused to give their support to the deal.
British and E.U. negotiators had been in intense talks for days as the deadline approached. “We’ve got a great new deal that takes back control — now Parliament should get Brexit done on Saturday,” British Prime Minister Boris Johnson tweeted, referring to the next step in the process, where U.K. lawmakers must ratify the deal.
Jean Claude Juncker, the E.U. Commission President, also welcomed the deal on Twitter. “Where there is a will, there is a deal – we have one! It’s a fair and balanced agreement for the E.U. and the U.K. and it is testament to our commitment to find solutions,” he wrote.
It remains unclear whether the U.K. Parliament will ratify the deal. Reports said the Democratic Unionist Party, Johnson’s minority government allies from Northern Ireland, had refused to support the agreement announced on Thursday morning.
The land border between Northern Ireland and the Republic of Ireland, which after Brexit will become the only land border between the U.K. and the E.U., had been a key point of contention in the negotiations.
The leaders of all E.U. member states and a majority of members of the European Parliament in Brussels must also ratify the deal in order for it to become effective. The previous deal, struck by Johnson’s predecessor Theresa May, passed both those hurdles but was brought down by U.K. lawmakers.
Britain’s official opposition Labour Party also said it would vote against the deal, and called for a second Brexit referendum. “From what we know, it seems the Prime Minister has negotiated an even worse deal than Theresa May’s, which was overwhelmingly rejected,” Labour leader Jeremy Corbyn said.
In a letter to European Council President Donald Tusk, Juncker said the negotiators had reached a new agreement on Northern Ireland.
If U.K. lawmakers reject the new deal in a vote on Saturday, Johnson must by law ask the E.U. for an “extension” — delaying Brexit beyond Oct. 31.
This is a developing story. Please refresh for updates.
More Must-Reads from TIME
- Introducing the 2024 TIME100 Next
- The Reinvention of J.D. Vance
- How to Survive Election Season Without Losing Your Mind
- Welcome to the Golden Age of Scams
- Did the Pandemic Break Our Brains?
- The Many Lives of Jack Antonoff
- 33 True Crime Documentaries That Shaped the Genre
- Why Gut Health Issues Are More Common in Women
Write to Billy Perrigo at billy.perrigo@time.com