British MPs on Monday defeated yet another attempt by Prime Minister Boris Johnson to force an early election, just hours after the European Union agreed to postpone Brexit for up to three months.

The Conservative leader immediately announced an alternative plan to hold a snap poll that could yet see an election in early December.

Johnson suffered a major setback earlier Monday when he was forced to agree to delay Britain's departure from the European Union beyond this week's October 31 deadlineBrexit .

He had previously said he would rather be "dead in a ditch" than extend the tortuous Brexit process started by the 2016 EU referendum.

But he was forced by law to ask EU leaders for what is the third postponement, after MPs refused to endorse the divorce terms he struck with Brussels earlier this month.

Ambassadors from the other 27 EU member states agreed to the request on Monday but proposed that Britain could leave earlier if the deal is ratified.

Johnson sought to regain the initiative by calling an election for December 12, with a plan to persuade MPs to back his agreement before then.

His initial proposal was defeated late Monday in the 650-seat House of Commons, as he failed to muster the required two-thirds majority.

But he immediately put forward a second plan to legislate for a poll on December 12 -- which would require only a simple majority to pass.

"This house cannot any longer keep this country hostage," Johnson told MPs.

He added: "We have a great new (Brexit) deal, and it's time for voters to have a chance to pronounce on that deal and to replace this dysfunctional parliament with a new parliament that can get Brexit done."

Flextension

The EU's approval came just three days before the latest Brexit deadline, a decision held up by scepticism in France about giving yet more time to a deeply divided British parliament.

"The EU27 has agreed that it will accept the UK's request for a Brexit flextension until 31 January 2020," European Council President Donald Tusk said.

Johnson accepted the offer in a letter to Tusk and other EU leaders a few hours later, but made clear his reluctance.

He urged EU members states "to make clear that a further extension after January 31 is not possible. This is plenty of time to ratify our deal".

According to a copy of the agreement seen by AFP, if Johnson convinces MPs to approve an amicable divorce accord in the coming weeks, Brexit could be on November 30 or December 31.

This is not impossible -- MPs last week backed Johnson's deal in principle but refused to rush through its ratification before October 31.

However, the legislation required to implement the treaty could get bogged down in the scrutiny process, and some supporters could yet change their minds.

In the meantime, the EU text says London must nominate a senior official to serve on the next European Commission and must agree not to try to reopen the divorce agreement.

After London gave its formal approval, Tusk will ask the EU capitals to sign off on it, likely on Tuesday or Wednesday.

Election wrangling

More than three years after Britons voted 52-48 percent for Brexit in a 2016 referendum the country and parliament remain deeply divided over when, how and even whether to leave the EU.

Johnson has tried twice before to force an election to break the political impasse.

The main opposition Labour party dislikes Johnson's Brexit deal and says it will not back an election until his threat of leaving the EU with no deal at all is removed.

"This is a prime minister who cannot be trusted," Labour leader Jeremy Corbyn told parliament. "Every promise this prime minister makes he abandons."

Some MPs fear that if the deal does not pass parliament, Johnson might delay an election until February, risking a "no deal" exit that many fear would cause huge economic disruption.

After losing Monday's vote, the premier announced he would introduce a bill on Tuesday to legislate for an election, which would enshrine a date in law.

Two smaller parties, the Scottish National Party and the Liberal Democrats, had earlier offered their own similar bill for a December 9 election.

SNP Westminster leader Ian Blackford said Johnson's legislation must guarantee that he will not try to ratify his Brexit deal before any election.

"We don't trust this prime minister," he said.

Copyright AFP. All rights reserved.

Boris Johnson loses early election bid
Prime Minister Boris Johnson is struggling to get parliament to agree to his demand for an early election. Photo: AFP / ISABEL INFANTES