EU states are preparing to grant Britain a Brexit extension until January 31 2020 after Brussels won French backing for a delay.
Under a proposal circulated to EU27 governments on Sunday, and seen by the Financial Times, the EU would grant Britain's request for a Brexit delay until the end of January, while leaving open the possibility for it to leave on December 1 2019 or on New Year's Day if its withdrawal treaty has been ratified.
French officials predicted there would "very probably" be an agreement on Monday among the EU27 for a Brexit extension until January 31 following negotiations over the weekend and a telephone call on Sunday afternoon between French president Emmanuel Macron and Boris Johnson, the UK prime minister.
The plan, which is set to be discussed by national ambassadors in Brussels on Monday morning, would also see EU leaders "firmly" exclude any reopening of Mr Johnson's Brexit deal, ruling out further negotiations on the terms of the UK's departure after more than two years of talks.
Leaders would also underline Britain's obligation to nominate a member of the next European Commission to serve until the UK's departure. This is something Boris Johnson has so far refused to do.
France irritated some of its EU partners last week by standing alone in resisting the idea of a three-month extension, but the officials said Mr Macron believed the extension was justified now that he had been convinced a UK election was imminent. Paris always insisted that long extensions should be granted not to allow further discussions and delay but only to take account of new situations such as a UK general election or a new referendum.
"It's true that France had a fairly tough position," said one official. "But there is now the perspective of quick British elections, which changes the picture."
The plan comes as the Liberal Democrats and Scottish Nationalists on Saturday said they would support a motion to hold a UK general election on December 9.
One EU diplomat said they expected the deal to win the necessary support at the ambassadors meeting on Monday morning. "Constructive talks have gone on throughout the weekend. There is now a good proposal on the table that should make it possible to find consensus," said the diplomat.
The extension would run to January 31 inclusive at the latest, meaning the UK's exit treaty would take effect on February 1. A further UK request and EU decision would be needed to extend any further beyond this.
EU diplomats said that the plan now on the table had been drawn up with French involvement. As well as ruling out any further negotiation on the UK's withdrawal agreement, the text reiterates requirements attached to previous Brexit extensions for Britain to behave in a "constructive" way during its remaining time as an EU member state, and to "refrain from any measure that could jeopardise the attainment of the Union's objectives".
An extension requires unanimous approval by EU27 leaders. Donald Tusk, the EU council president, has been pushing for an extension to January 31, in line with Mr Johnson's request this month.