Deliberations in Brussels over a Brexit delay have continued into the weekend, as a leaked document indicates the UK could deviate away from EU employee and environmental rights after exit day.

After a meeting of European Union ambassadors on Friday, a Brussels source said there was “full agreement on the need for an extension” and that “work will continue over the weekend”.

A final decision on whether they will opt for an extension until January or a shorter November delay – thought to be favoured by French President Emmanuel Macron – is not expected until Monday or Tuesday.

The weekend talks among the EU27’s teams are likely to be coloured by a leaked document, seen by the Financial Times, that indicates the Government could look to diverge away from the bloc’s rules on workers’ rights and environmental protections after Brexit.

There are fears in some quarters of the EU – and especially in Berlin – that Boris 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.

According to the FT’s report, the leaked Department for Exiting the European Union (DExEU) document said the way the political declaration – the agreement setting out the aims of the future trade negotiations between the UK and the EU – had drafted the workers’ rights and environmental protection commitments left “room for interpretation”.

Mr Johnson this week told MPs the UK was committed to “the highest possible standards” on both sets of standards – a stance that helped to convince 19 Labour MPs to back his Withdrawal Agreement Bill at second reading on Tuesday.

The document is said to boast that “UK negotiators successfully resisted the inclusion of all UK-wide level playing-field rules” in the previous deal negotiated by Theresa May’s team, allowing Britain to compete against EU members by possibly watering down rights.

Labour shadow Brexit minister Jenny Chapman said the documents, which reportedly had Downing Street input, “confirm our worst fears”.

She said: “Boris Johnson’s Brexit is a blueprint for a deregulated economy, which will see vital rights and protections torn up.”

The Prime Minister visited a hospital on Friday and used interviews afterwards to call on opposition leader Jeremy Corbyn to “man up” and agree to a general election.

It follows the Conservative Party leader announcing on Thursday that he was prepared to give MPs more time to debate his Brexit deal in exchange for their support for a winter election on December 12.

Brexit Party chairman Richard Tice has offered a “Leave alliance” to Mr Johnson at the poll as long as he ditches his Withdrawal Agreement and campaigns to take Britain out without a deal.

Mr Corbyn has so far said Labour is waiting to see the result of the EU’s decision regarding the length of an Article 50 extension before clarifying whether he would whip MPs to back a fresh poll.

But senior figures in the party have urged him to deny Mr Johnson and instead continue to push for a second referendum and for a no-deal Brexit to be removed as an option.

Both Tony Blair, a former prime minister who won three general elections, and London Mayor Sadiq Khan called for him to stand firm.

I think he should go a bit further and be unequivocally pro remain and explain to those who are Brexiteers why he disagrees with them and have the argument Sadiq Khan on Jeremy Corbyn's Brexit stance

Mr Blair said Labour could not trust Mr Johnson not to push through a no-deal Brexit and should withhold permission for an election while the PM is void of a majority.

“That’s the core reason why, in my view, the Labour Party should not allow an election until he gives a definitive answer on the question of whether there’s going to be a no-deal outcome,” he told talkRADIO in a pre-recorded interview for Sunday.

Mr Khan, speaking to Italian newspaper La Repubblica, encouraged Mr Corbyn to be “braver” and start telling Leave voters they were “wrong”.

“I’d like the Labour Party to be braver and provide leadership on this issue,” said the former MP.

He added: “I think (Mr Corbyn) should go a bit further and be unequivocally pro remain and explain to those who are Brexiteers why he disagrees with them and have the argument.”

Whether there is a snap election or not, Diana Johnson discovered on Friday evening that she will be the Labour candidate again in Hull North the next time the PM goes to the country.

Last month she became the first MP to be triggered for a re-selection battle following the introduction of new watered-down rules.

Ms Johnson, who has won the seat four times since 2005, defeated city councillor Aneesa Akbar by 292 votes to 101.

Meanwhile, Mr Johnson’s advisers will be hoping he is easier to deal with in any future election, in the winter or otherwise, than his predecessor.

According to historian Sir Anthony Seldon’s new biography May At 10, Mrs May was “surly” and a “terrible campaigner” during the snap 2017 election she called, even requiring a full-time “minder”.