Boris Johnson leadership bid in disarray as debate cancelled over no-show and Tory MPs threaten to collapse his government - as it happened

The Brexit Party has called for an investigation into the result of the Peterborough by-election earlier this month and made allegations of "vote-rigging".

The election was won by Labour's Lisa Forbes by just 683 votes, with the Brexit Party in second place.

At a press conference in London, Nigel Farage, the leader of the party, raised concerns about the impact that postal votes had had on the result.

He said: 

"It's about a system that is wide open to corruption, to intimidation, to bribery, to abuse on a whole number of levels."

"If you say it's sour grapes, you can say it, but actually it is time for change and my ambition would be that by the next general election to get rid of the current postal vote system."

Richard Tice, chairman of the Brexit Party, said there had been multiple "rumours" of wrongdoing, including "vote-rigging". He claimed a "convicted electoral fraudster" had acted as an election agent for Labour.

Announcing that the party will launch a formal appeal that could result in the outcome being challenged in the courts, he said:

"How much did Lisa Forbes, the elected MP, know that she had a convicted electoral fraudster in her team who would count as an agent?"

Cambridgeshire Police said no offences have been uncovered during its investigation into one allegation of bribery and two relating to postal vote.

Ken Clarke becomes the latest Conservative MP to suggest he would be willing to bring down the government to block a no-deal Brexit.

Asked what he would do if Labour triggered a vote of no confidence, the former chancellor tells BBC Radio 4's World at One:

"It depends on the circumstances at the time and what whoever is prime minister is putting forward as the policy he is going to pursue.

"But I am not going to vote in favour of a government that says it is going to pursue policies which are totally incompatible with everything the Conservative Party has stood for under all those prime ministers for the decades that I have been in parliament."

"The ambiguous shuffle by the shadow cabinet towards backing a Final Say referendum on any Brexit deal is a significant moment on a long road from Jeremy Corbyn’s acceptance, on the day after the 2016 vote, that Labour would respect the decision to leave the EU," writes John Rentoul.

"The Labour leader has long been criticised by Remainers who refused to give up the fight to stay in the EU. He was a lifelong “better off outer”, they said, who tempered his views during the referendum but then prevented Labour from opposing Brexit – thus ceding ground and millions of votes to the Liberal Democrats, Greens and nationalists."

There is “absolutely no evidence” that Russia used Facebook to influence the outcome of the EU referendum, the technology giant’s vice-president, Sir Nick Clegg, has insisted.

The former deputy prime minister said the social media company had analysed its data and found no “significant attempt by outside forces” to sway the Brexit vote.

He also dismissed suggestions that Cambridge Analytica, which harvested the data of up to 87 million Facebook users, had influenced the UK’s decision to leave the EU.

Labour has hit back strongly at claims that its victory in the Peterborough by-election earlier this month involved "vote-rigging". 

The Brexit Party made the allegations at a press conference earlier today, and said it would be launching a formal appeal against the result. It claimed one of Labour's electoral agents was "a convicted electoral fraudster".

But a Labour spokesperson said:

"This is nonsense. This person was not an agent for the Labour Party and was not involved in the running of Labour's campaign in any way. This is a desperate attempt by the Brexit Party to make excuses for their defeat. Labour won the Peterborough by-election fairly and squarely."

Tory grandee Sir Nicholas Soames, not a fan of Boris Johnson by any measure, adds to pressure on the leadership frontrunner to start answering some questions...

Tory MPs have been given a three-line whip for the last week of July, Sky News is reporting, in preparation for Labour tabling a no confidence motion as soon as the new prime minister is announced.

We're expecting Theresa May to give a statement any minute now on last week's European Council summit - her last as prime minister. These statements used to be major events, with MPs crowding into the Commons to grill the prime minister on Brexit, but the chamber is currently more than half empty. That's partly because the summit was not one at which Brexit was officially discussed, and partly because, politics being a rather brutal world, people are no longer particularly interested in what the outgoing prime minister has to say.

Theresa May says last week's European Council meeting was, in fact, not her last as prime minister. There was no consensus on who should take over as presidents of the European Commission and the Council, she says, meaning another summit will take to take place next week, after the G20 summit in Japan this weekend.

Responding to Theresa May's statement, Jeremy Corbyn makes a number of references to a second referendum - something he has previously been criticised for not mentioning at all.

He asks Ms May:

"What would be worse: crashing out with no deal in October, or putting this issue back to the people for a final say?"

and wraps up by saying:

"Whatever Brexit plan the new Tory leader comes up with, after three long years of failure they should have the confidence to go back to the people on a deal agreed by parliament."

Many Labour MPs will welcome that sort of language.