Brexit impasse, as UK and EU refuse to move first

"If I win a majority in this election, we will then ratify the great new deal that I have negotiated, get Brexit done by January and the country will move on," Johnson wrote to Corbyn.

"If you win a majority, then you will, I assume, implement your policy: that is, you will ask for another delay after 31 January 2020, to give you the time both to renegotiate a new deal, then have a referendum, in which you may or may not campaign for your own deal," he said.

"It is time for MPs finally to take responsibility," Johnson went on, adding that "given the situation we must give the voters the chance to resolve this situation."

It is not yet clear how Corbyn will react.

Although Labour had been in favour of new elections in the past, Corbyn wants to first exclude the possibility of a no-deal Brexit before heading to the urns.

He is also likely to wait until the EU has decided what kind of delay it wants to give to the UK before making up his mind. And the EU decision might be taken on Friday.

"No-deal is a threat that Boris Johnson has been using all along, and indeed it's included in his legislation that's before parliament at the moment, the legislation that he's paused," Corbyn said on Thursday.

"I want us not to crash out of the EU because of all the damage it will do to jobs across the country. We'll know tomorrow [Friday, 25 October] what the extension will be and I can answer that question tomorrow. What I'm saying now is, take no deal off the table," he added.

Internally, Labour seems to be divided on whether or not elections on 12 December are a good idea.

Momentum, the campaign group that supports Labour, says they are ready for them.

"Bring it on", Laura Parker, Momentum's national coordinator, said on the Johnson gambit.

"Our campaign will see tens of thousands of people talk to millions of voters across the country. In 2017 Momentum's campaign swung key seats for Labour. This time we're going to run the biggest people-powered campaign the country has ever seen," she added.

But others are much less enthusiastic, claiming that campaigning for elections in winter is a bad idea.

Waiting for Europe

For their part, European leaders and the European Parliament have already said they were in favour of giving the UK another delay.

How long the extension might be will be discussed by envoys of the EU member-states on Friday in Brussels.

According to a draft decision, seen by Reuters on Thursday evening, the EU might go for what one diplomat called a "flextension" - combining both "flexibility" and "extension".

In this proposal, the UK would be granted a new delay of three months, but with the possibility to leave earlier if a Brexit deal is concluded before 31 January.

"Consequently, the withdrawal should take place on the first day of the month following the completion of the ratification procedure, or on (blank), whichever is earliest," the draft decision said.

France, on the other hand, remains sceptical and might prefer to wait for the UK's decision whether or not to have elections.

According to French European affairs minister Amelie de Montchalin: "The French position is to give more time if it's justified, if we understand why we're doing it; some time to ratify obviously ... If we're told 'We want to have elections,' we'll look at the question of elections."

But if France sticks to its position, it creates an impasse in which the EU will not decide before the UK makes up its mind, while Labour does not want to decide before the EU makes up its mind either.