Theresa May is heading for top-level Brexit talks in Berlin and Paris as she seeks support for another extension.
The Prime Minister is embarking on a diplomatic flurry which will see her meet German Chancellor Angela Merkel and French President Emmanuel Macron ahead of a crunch EU summit on Wednesday.
All 27 remaining EU heads of government must agree to an extension if the UK is to avoid the default position of a no-deal Brexit on Friday night.
According to reports, Brexit could be delayed by nearly a year under plans being considered by EU officials.
Mrs May is expected to ask the EU for an extension to June 30 in order to get a deal through Parliament.
On Monday night, MPs and peers backed a new law to extend the Brexit process and cross-party talks are expected to continue in the hope of finding a compromise.
Ahead of Mrs May’s meetings with her French and German counterparts, details of the EU’s potential demands for another extension to the Article 50 period began to emerge in reports.
If a deal is not passed by MPs by Friday, the EU leaders could be asked to consider a nine or 12-month extension, until December 31 2019 or March 31 2020.
Such an extension would mean the UK had to take part in European parliamentary elections, a prospect anathema to hardline Brexiteer Tories, and could be sidelined from budget decisions in Brussels.
The obligation for the UK to be a good partner emerged after Jacob Rees-Mogg, chairman of the European Research Group of Brexiteer Tories, said Britain should use its powers “to be difficult”.
On Monday night, the Commons backed a series of Lords amendments to the European Union (Withdrawal) (No 5) Act after it was rushed through both Houses of Parliament.
The cross-party move brought forward by Yvette Cooper and others led to Mrs May tabling a Commons motion for debate on Tuesday setting June 30 as the extension date.
The move came as the Government and Labour were holding talks on trying to break the Brexit deadlock.
After officials from the two sides met on Monday, the fresh round of talks will include Mrs May’s de facto deputy, Cabinet Office Minister David Lidington, and shadow Brexit secretary Sir Keir Starmer.
Labour leader Jeremy Corbyn has called on the Government to be more flexible regarding red line issues in the talks.
In a bid to end the deadlock with Labour, the Prime Minister is considering offering MPs a vote on whether to hold a referendum on any deal agreed on Brexit, according to the Daily Telegraph.
Senior backbench Tories visited Mrs May in Downing Street on Monday and it is understood concern was expressed about the possibility of agreeing to a customs union as a price for a deal with Labour.
And in Tuesday’s Daily Telegraph, Tory grandee William Hague said the talks were “akin to having a dinner date with a crocodile”.
Lord Hague wrote: “It is difficult in any case to see how carrying through the programme of Brexit procedures and laws could be sustained by an agreement between part of the Conservative Party and the bulk of the Labour Party – the Government would be highly likely to collapse under such a strain.”
The cross-party discussions are taking place as the Tories launch a selection process for candidates to stand in European Parliament elections next month.
The Financial Times reported that the Tory Party was rushing to line up candidates for the EU parliamentary elections on Monday night.
The Government earlier tabled an order enabling the elections to be held in Britain if the country has not left the EU by the time they are due to take place on May 23.
The Cabinet Office said the elections would be cancelled automatically if the UK left before then.
European Council president Donald Tusk has recommended a one-year extension to the Brexit process, with a break clause allowing an earlier departure if a withdrawal deal is ratified in Westminster.