The sources said the prime minister was confident that the election motion would receive the two-thirds majority required to trigger an early poll under the Fixed Term Parliaments Act.
Ministers will table the motion by the end of Tuesday, but it will be moved to a vote on Wednesday only if MPs vote tomorrow to take control of Commons business in order to pass a bill to block a no-deal Brexit on 31 October.
In an unexpected statement outside Number 10 on Monday, Mr Johnson insisted there were “no circumstances” in which he would delay Brexit beyond the current deadline.
The prime minister warned that MPs would “chop the legs out” from the UK position if they backed a Brexit extension as he addressed the nation this evening.
Please allow a moment for the live stream to load
Good morning and welcome to The Independent's live coverage of events at Westminster.
Shadow business secretary Rebecca Long-Bailey warned that this week is the “last chance” to stop a “disastrous” no-deal departure.
She told the Today programme that this was because of the “constitutional outrage” of Boris Johnson’s suspension of Parliament.
The Labour MP also said she supports all lawful and peaceful protests against no-deal and did not rule out backing those who plan to occupy Parliament.
Asked about the move proposed by the Momentum group, she said: “As long as it’s peaceful and it's within the law, then I would have no problem with it. I think everybody has the right to voice their concerns and to protest.”
Tony Blair is calling for Labour to oppose any move by Boris Johnson to hold an emergency general election until Brexit has been resolved.
The former PM is making a speech at the Institute for Government today and he is expected to say that Jeremy Corbyn should not “fall into the elephant trap” of backing a Westminster poll if MPs cannot agree on Brexit.
Blair will say Labour should throw its weight behind supporting legislation to prevent a no-deal Brexit, not a vote of no confidence in the government.
“Should the Government seek an election, it should be refused in favour of a referendum. It is counter-intuitive for opposition parties to refuse an election.
“But in this exceptional case, it is vital they do so as a matter of principle, until Brexit is resolved. Brexit is an issue which stands on its own, was originally decided on its own and should be reconsidered on its own.
“But the Brexiteers are laying a trap, to seem as if pushed into an election against their will, when they're actively preparing for it.”
Blair is set to praise Labour leader Jeremy Corbyn for his recent willingness to work with other parties.
“In backing away from the idea of himself as a ‘caretaker prime minister’ Jeremy Corbyn has behaved responsibly, and if he continues to put country first, he will benefit the country and himself.
“He can now play a decisive role in how Brexit develops. But he should see an election for the elephant trap it is. If the government tries to force an election, Labour should vote against it.”
Former Tory minister David Gauke has accused Boris Johnson of “goading” some Tories to rebel against the Government so they can be purged from the party and a general election can be forced.
The key no-deal Brexit opponent said the PM’s move to put Tory rebels on notice that they face losing the whip was an “unusual approach”.
“It’s obviously a particularly confrontational approach and, I think, designed, frankly, to realign the Conservative Party, to transform the Conservative Party very much in the direction of a Brexit party,” Mr Gauke told BBC Radio 4’s Today programme.
The MP said he had not heard from party whips in an attempt to convince him to support the Government.
“I don’t think there seems to be a huge effort to persuade people to support the government this week. I think they seem to be quite prepared for there to be a rebellion then to purge those who support the rebellion from the party.
“Normally there would be plenty of cajoling. One would have friends from the cabinet phoning up and saying ‘Come on, why don’t you support the government, give them a bit more time?’
“None of that is happening. The usual operation isn’t particularly happening. It does seem to me they are almost goading people into voting against the government.
“Because I think the strategy, to be honest, is to lose this week and then seek a general election, having removed those of us who are not against Brexit, not against leaving the European Union, but believe we should do so with a deal.”
Rebel MPs have been told they could have the whip removed and would be banned from standing as Conservative candidates in the next election – if they vote with the opposition this week.
Here’s Lizzy Buchan with all the details.
Shadow Brexit secretary Keir Starmer is among the MPs suggesting the legislation designed to block a no-deal Brexit on 31 October could be surprisingly simple.
On Sunday Michael Gove hinted the precise wording of any bill would matter – and sparked fury by refusing to say whether the government would abide by any legislation passed.
The opposition is keen to avoid giving the government any wiggle room whatsoever.
“The legislation is intended to ensure we don’t leave without a deal, that will require an extension,” said Starmer. “The length of the extension is secondary, frankly. We have simply got to stop us leaving without a deal.”
“Obviously if we’re at the 31 October that will require an extension. But I think this should be a very short, simple exercise designed to ensure we don’t crash out without a deal.”
Lib Dem MP Chuka Umunna echoed the idea on the Today programme.
“We believe that MP colleagues would be making a grave mistake if they throw all their eggs into the basket of legislating to extend Article 50 because we saw from the Vote Leave campaign, let’s face it they now run the government, that we’ve got a group of people here who are prepared to lie, to cheat and break the rules to win at any cost,” he said.
“So, even if the Commons successfully legislates to get an extension, it may not necessarily work. The government may find a way around it.”
David Gauke had plenty to say on the Today programme this morning.
As well as accusing Boris Johnson of “goading” him and his fellow Tory rebels into voting with the opposition so a general election can be forced, he also warned there is a 95 per cent chance of a no-deal Brexit if MPs cannot legislate against the event, as he accused the Government of having no credible plan to leave with a deal.
Gauke also said he has written to Attorney General Geoffrey Cox after Michael Gove refused to confirm whether ministers would abide by any law passed.
“I think it would be very helpful if the Government could clarify that they believe in the rule of law,” he said, before adding that he wanted “to get confirmation that this government believes in the rule of law, that it will comply with the law, and if legislation is properly passed it will be complied with.”
Lib Dem leader Jo Swinson wants the Operation Yellowhammer dossier of no-deal Brexit impacts released in full.
The party’s Brexit spokesperson Tom Brake has already written to cabinet secretary Sir Mark Sedwill urging him to let the public see an unedited version following reports Michael Gove is trying to “soft soap” and “sanitise” the document before its possible release next week.
Tony Blair is speaking at the Institute of Government this morning. He claimed the government had “been taken over by a gang of adventurers … posing as the saviours of the people”.
He has also warned Jeremy Corbyn not to “fall into the elephant trap” of backing a general election if MPs cannot agree on Brexit. “The Brexiteers are laying a trap, to seem as if pushed into an election whilst actively preparing for one.”
The former prime minister has also said the consequence of Brexit is to “diminish Britain globally".
“In a short amount of time the world will be big global blocks - USA, China and probably India. [The EU] is not about peace, it is about power."
Britain “should retain its special relationship with America but its natural home is in Europe,” he added.
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies