Theresa May is set to write to European Commission president Donald Tusk to lay out the government's plan for delaying Brexit.
The cabinet spent 90 minutes discussing the issue this morning but reportedly did not reach a conclusion on the possible length of the extension.
It comes as European leaders signalled that they may not agree to the UK’s request for a delay to Britain's departure from the bloc, which was originally expected on March 29.
German Europe minister Michel Roth said EU leaders were “really exhausted” with the Brexit saga and and demanded “clear and precise” proposals from the UK government.
To follow events as they unfolded, see our live coverage below
Ms May was reported to be planning a third "meaningful vote" on her deal this week, although Downing Street said it would only happen if there was a "realistic prospect" of success.
Theresa May's hopes for passing Brexit deal in tatters after Bercow rules out repeat vote
Both no-deal and fresh referendum supporters delighted - while minister floats extraordinary plan to suspend parliament and start a new sessionWhat is the role of the Speaker of the House of Commons?
The familiar shout of "Order, order!" explains part of the Speaker's job in Parliament. They are in charge of keeping order during debates, and calling different MPs to take their turns speaking on various issues.
What powers does the Speaker have?
The Speaker is the highest authority in the House of Commons and has the power to ensure MPs follow the rules, including asking them to be quiet while others are speaking, directing a member to withdraw remarks if they are deemed to be abusive, and suspending the sitting of the House if there is judged to be serious disorder. An MP can be suspended if they are felt to have been deliberately disobedient.
Is the Speaker impartial?
The speaker is an elected MP, like all their colleagues in the House, and they are supposed to deal with constituency business as normal. However when elected they are required to resign from their political party and to keep themselves separate from political issues, remaining impartial.
How is the Speaker elected?
The current speaker was elected in 2009, using an exhaustive secret ballot system. MPs marked an X next to the candidate of their choice on a list. John Bercow got 322 of the 593 ballots cast, at which point the question proposing the successful candidate as Speaker was put before the House and he took the chair.
How has the current Speaker enforced the rules most recently?
Mr Bercow cited the Commons rulebook Erskine May - the authoritative book on parliamentary law and practice - as he set out a convention dating back to 1604 that a defeated motion cannot be brought back in the same form during the course of a parliamentary session.
His ruling, which came in an unexpected statement to the Commons on Monday, indicated that the Prime Minister cannot bring her EU Withdrawal Agreement back before MPs unless it is substantially different from the package which was decisively defeated last week.
Brexit Secretary Stephen Barclay has signalled that ministers will continue to press on with Theresa May's Brexit deal despite the Commons Speaker's bombshell intervention.
Speaking on Sky News, Mr Barclay said:
"What we need to do is secure the deal. This is the only deal on the table. The EU is clear it is the only deal on the table.
Business need the certainty of this deal and it is time that Parliament comes together and gets behind it."
"What the Speaker has said in his ruling is there needs to be something that is different. You can have the same motion but where the circumstances have changed.
"So we need to look at the details of the ruling, we need to consider that in the terms of earlier rulings that don't particularly align with yesterday's.
"The fact a number of Members of Parliament have said that they will change their votes points to the fact that there are things that are different."
The European Union needs clarity from London on Brexit, a Romanian minister said in Brussels on Tuesday before chairing talks among his European peers.
George Ciamba, EU affairs minister for Romania, which now holds the bloc's rotating presidency, said:
"We need to have more clarity from London. Clearly, there is no clarity, there is less clarity today than there was yesterday.
It's about political will and a little bit more clarity about what Europe could do ... There are things we cannot do, like renegotiating the withdrawal agreement."
Opinion: John Bercow’s ruling has changed everything – Europe now decides the fate of Brexit
A short delay could give us the breathing space to come up with a solution. A longer period such as the 21 months floated by Macron may make a hard Brexit more likelyIn a joint statement ahead of the talks, Ian Blackford, Sir Vince Cable, Liz Saville Roberts and Caroline Lucas said: "The UK faces an unprecedented crisis with Brexit, and Westminster remains deeply divided.
"The best and most democratic way forward is to put the decision back to the people in a new vote - with the option to Remain on the ballot paper."
