A senior EU official has told Sky News the bloc is “very unlikely” to decide on an extension to Brexit negotiations before Tuesday.
EU leaders are deciding whether to opt for an extension until January or a shorter November delay – thought to be favoured by French President Emmanuel Macron.
It was thought they would decide by Tuesday – two days before the latest official leaving date – but this is now looking unlikely, meaning Boris Johnson will be unable to fulfil his promise of leaving on 31 October “do or die”.
Latvia’s foreign minister, Edgars Rinkevics, said on Saturday: “There has been unanimous agreement that we need to extend the Brexit discussion.
“There is a big discussion of what is the best deadline, and I wouldn’t make drama out of it.”
Weekend talks by the 27 leaders are likely to be influenced by a leaked document, seen by the Financial Times, that indicates the British government may want to diverge away from the bloc’s rules on workers’ rights and environmental protections after Brexit.
There are fears by some EU nations, especially Germany, that Mr Johnson is preparing to reform Britain into “Singapore-on-Thames” – a low-tax, lightly regulated economy on the edge of Europe – once it has left.
Mr Johnson is pressing on with calls for an election and will ask MPs to vote on Monday for a 12 December general election to give them more time to debate his Brexit deal.
The prime minister told Jeremy Corbyn on Friday to “man up” and face him after the Labour leader said he is waiting to see what the EU’s decision is over extending the Article 50 negotiating period before clarifying whether he would tell his MPs to back a fresh poll.
Political opponents at Westminster had been holding out for an extension to be granted and so removing the imminent threat of a no-deal exit, before backing an election.
The prime minister has said he would give MPs more time to consider his Brexit deal if they backed his call for a poll on 12 December.
He needs opposition votes in order to secure the two-thirds Commons majority required by law to hold a national ballot.
In the face of being thwarted over his repeated pledge to leave the EU by 31 October, the PM sought to exploit Labour divisions over a pre-Christmas election.
“Time for Corbyn – man up. Let’s have an election on December 12,” he said.
While Mr Johnson insisted Britain could still leave the EU by the current Halloween deadline, he admitted the decision now lay with the EU, as a result of legislation agreed by parliament, which he again branded “the surrender act”
He said: “Let’s be clear, this parliament has been sitting now doing absolutely nothing but delay Brexit, pushing it out with delay after delay for three-and-a-half years.
“And I think for MPs across the House to have any credibility about delivering Brexit they now have to commit to an election 12 December. So that’s what we’re pushing for.”
Mr Corbyn has said he will back a general election if the PM removes the threat of a no-deal Brexit.
The Labour leader told ITV: “I’ve said all along – take no deal off the table, and we’ll have the election.”
But many of his MPs oppose a poll, seeing advantage in keeping the PM in political limbo, while also fearing confusion over the party’s stance on Brexit could lose them votes.
Shadow home secretary Diane Abbott said they wanted an “explicit commitment” a no-deal Brexit was off the table before they would be prepared to back an election.
Indicating they could require further legislation, she told the BBC: “The December day is a ludicrous day. We’ve not had a general election at Christmas for over a century, and there’s good reasons for that.”
Earlier, Chancellor Sajid Javid told Sky News of the need to “put an end to this dysfunctional parliament”.
On holding a December election, Mr Javid said: “It’s highly unusual and not ideal but what’s the alternative.
“If we don’t have this election then we will continue with this zombie parliament.”
Downing Street has also indicated it could effectively “work to rule” if it fails to get an election.
A spokesman for the PM said: “Nothing will come before parliament but the bare minimum.
“We will pursue a general election every day from then onwards and do everything we can to get it.”
Following the meeting of EU ambassadors on Friday, the European Commission’s chief spokeswoman, Mina Andreeva, said: “The EU 27 have agreed to the principle of an extension and work will now continue in the coming days.”
They are expected to meet again on Monday or Tuesday to finalise an agreement.
The prime minister was forced by parliament to write to Brussels requesting the delay after failing to win backing for the agreement he reached with Brussels at last weekend’s special Saturday sitting.
Many MPs also argue his proposed election timetable, requiring them to approve the withdrawal legislation by 6 November when parliament would be dissolved, is still not long enough to allow proper scrutiny.