In a speech at JCB Cab Manufacturing Centre’s headquarters near Uttoxeter, the Prime Minister called Jeremy Corbyn a ‘Hamas-backing, IRA-supporting, anti-Semitism-condoning appeaser of the Kremlin’.

The prime minister also said the leaked comments made by shadow secretary Jon Ashworth, were proof Labour was losing votes over its Brexit stance.

He was referring to a leaked recording of a conversation between Mr Ashworth and a Tory activist, in which Mr Ashworth says Jeremy Corbyn is a security risk and that he didn’t believe he could win an election.

Mr Johnson said: ‘If you doubt me, look at what his health spokesman said today, Jon Ashworth. He revealed that he thought his own leader is a security risk.

‘And there is another fact Mr Ashworth mentioned, which I think is even more terrifying when you look at the year ahead and the prospects for our country.

Jon Ashworth made it absolutely clear that the reason Mr Corbyn is failing to persuade some people to vote for him is he is blocking Brexit – he won’t get Brexit done.

‘Don’t just listen to me, look at what his health spokesman Jon Ashworth has said. He is absolutely right.’

Meanwhile, Extinction Rebellion protesters, some dressed as bees, gathered around the Conservative campaign bus as it tried to leave JCB in Uttoxeter.

They appear to have stuck themselves to the vehicle.

Prime Minister Boris Johnson is not on board.

On the campaign trail today, Jeremy Corbyn insisted Jonathan Ashworth has his ‘full support’ after his key ally called him to say the criticism revealed in the clandestine recording was ‘reverse psychology banter’.

Mr Corbyn said that he was ‘cool with Jon’, after the shadow health secretary quickly called him following the recording’s publication on the Guido Fawkes website.

He added: ‘This is Guido Fawkes tapping into a private bit of banter between two old friends.

‘I’ve had a chat with Jon Ashworth; he called me straight away.

‘He’s out there campaigning for a Labour government, he’s out there defending our NHS, and Jon has my full support and I’m cool with Jon, we get along great.

‘He said to me it was all about reverse psychology banter as in football supporters and the other person was saying the opposite about their party and it all got a bit out of hand.’

A Labour Source, said: ‘These are absurd comments from Boris Johnson, who is desperately trying to distract from the crisis the Conservatives have created in our NHS that has left children sleeping on the floor of our hospitals.

‘He has no plan for our country so he resorts to baseless political attacks instead.

‘This is rank hypocrisy from Boris Johnson, who has today been criticised for using pernicious antisemitic tropes and conspiracies which fuel prejudice about Jewish people.

‘Johnson is the only one who is appeasing the Kremlin, taking donations from oligarchs linked to Putin and refusing to publish a report on Russian interference.’