Downing Street has confirmed that a draft Brexit agreement has been reached between the UK and European Union.
British Prime Minister Theresa May will present it to her senior ministers on Wednesday, but it is unclear if May will be able to get any deal approved by UK parliament.
"Cabinet will meet at 2 pm tomorrow to consider the draft agreement the negotiating teams have reached in Brussels, and to decide on next steps," a spokesman at May's Downing Street office said.
Ministers will also be invited to read the documents before the meeting.
British media were leaked documents of the breakthrough on Tuesday afternoon.
Euronews' UK Correspondent Vincent McAviney said: "Make no mistake, despite clutching an agreement text 24 hours before the deadline for a November EU summit, Theresa May won’t have time for any celebrations in Downing Street tonight".
"Whereas negotiations in Brussels have been binary dealing with a united EU 27 the fight to get this agreement through Westminster starts this evening and will be even tougher, " McAviney added.
The prime minister is calling in her cabinet ministers one by one tonight to show them the relevant sections of the agreement. They will not be able to take the text away and will have the night to sleep on it to decide if they will support May or resign, according to McAviney.
No immediate details of the deal have been supplied by the British government, but it is said to be hundreds of pages long.
With under five months until the Brexit divorce date of March 29, 2019, the issue of the so-called Northern Irish backstop was the main outstanding point.
It is not clear what has been agreed on with Ireland, whose border has remained open and free of tariffs since the 1998 Good Friday agreement.
Northern Ireland's Democratic Unionist Party, which props up May's Conservatives, has said it will not accept the UK agreeing to a customs border down the Irish sea, meaning the party could even vote against the government.
However, asked if the deal marks the end game for the relationship with the UK government, the DUP's deputy leader, Nigel Dodds, said on Tuesday evening: "No".
McAviney added: "Opposition MPs from Labour, the Liberal Democrats, and the SNP will almost all vote against the deal hoping to bring about a second referendum or even a snap election.
"The maths is looking difficult and for Theresa May the game of chess may be done with Brussels but getting enough votes in the Commons is going to be more like trying to solve a Rubix Cube, every side will present problems every which way she turns."
Hard Brexiteers have reacted negatively to the proposed deal. Jacob Rees-Mogg, the chairman of the European Research Group, said: “I hope Cabinet will block it, or if not, Parliament will block it.”
While former Foreign Secretary Boris Johnson said he believed the deal was “vassal state stuff”, adding that the UK would be subject to laws over which it could not control, which was “utterly unacceptable”.