A draft paper circulated among member states expected to be signed off tomorrow will let the UK leave earlier if it is able to finalise a deal.
According to the Guardian, the leaked document also rules out a no-deal Brexit on October 31, which UK opposition party leaders demanded as a condition for a general election.
It comes as European Council President Donald Tusk has been in talks with EU leaders over the weekend before ambassadors for the 27 member states meet tomorrow morning.
An deceleration attached to the paper says the bloc is not prepared to renegotiate the withdrawal deal.
The document, which is still subject to change, says Britain would be able to leave the EU on the first day of the month after a deal is ratified.
It also says the UK has an ‘obligation’ to select a candidate to join the European Commission, even if the country does not have much time left in the EU.
The paper suggests Tusk has successfully persuaded more hesitant members that a three-month extension is appropriate.
French President Emmanuel Macron’s push for an earlier November 15 Brexit deadline is not included in the document.
An extension was due to be signed off on Friday, but the French ambassador was the only EU diplomat who argued members should wait until Monday to decide whether to ‘go short, to push for ratification, or long to accommodate for a general election.’
The document is in line with the Benn Act passed by Westminster in September, which makes a no-deal Brexit illegal without Parliamentary approval and compelled Boris Johnson to ask for a delay if he could not secure a deal by Saturday last week.
UK voters look increasingly likely to go to the polls before Christmas now, after the Liberal Democrats and the SNP laid out a plan to trigger a snap general election on December 9.
This is three days before Johnson’s proposed date and is when more students are still at university to cast their votes in remain-supporting target swing seats.
If the EU approves a Brexit delay until January 31 as requested in Johnson’s letter to Brussels last week, the remain-backing parties would try to pass a bill allowing the Prime Minister to secure an election with a simply majority of MPs.
This would by-pass the two-thirds support usually needed to get one underway under the Fixed Term Parliaments Act.
If Johnson were to get an election this way, he will need Labour votes if he is to attempt to trigger one in the Commons tomorrow.
Labour leader Jeremy Corbyn said he will decide after inspecting the terms of the Article 50 extension granted by Brussels.
He has previously said: ‘Take no-deal off the table and we absolutely support a General Election.’
Downing Street said it would look at the proposal if the Labour Party does not support its plan for the withdrawal bill to be scrutinised by Parliament up to November 6 before a general election on December 12.