It is the “beginning of the end” for Prime Minister Boris Johnson, Brexit leader Nigel Farage said on Sunday, following the British leader’s ousting of Vote Leave director Dominic Cummings from Downing Street.

Mr Farage predicted that Johnson will use the departure of Cummings and the possibility of a Joe Biden presidency to push the Conservative Party to adopt a left-wing agenda, which he said will risk the support of working-class voters in Northern ‘Red Wall’ constituencies.

He said that Boris Johnson’s Conservative Party are “going to go green…they’re going to go big on trans rights, they’re going to go big on generally not causing offence to anybody, and I’ve no doubt taking the knee to BLM and other Marxist organizations.”

The leader of the Reform Party said that Mr Johnson is no “Winston Churchill or Margaret Thatcher” and argued that the PM is “always worried about short-term unpopularity”.

“I fear that if Boris is now being convinced by those around him the refreshed new lovely sort of Cameron approach to everything: let’s be cuddly and fluffy and lovely and popular in central London. If he thinks that is going to save his political career he’s in for the most almighty shock,” he said.

Farage predicted that in light of the departure of chief advisor Dominic Cummings and communications director Lee Kaine, he feels it will be “the beginning of the end for Boris Johnson”, whom he claimed has squandered the historic 80 seat victory in last year’s general election.

He argued that the Conservative Party has failed to understand the voters who helped secure their majority in Parliament, saying: “they are not interested in taxpayer-funded green ideas”.

The Prime Minister is expected to deliver a speech outlining his green agenda, which reportedly will seek to ban the sale of new petrol and diesel engine cars by the year 2030. While the speech was trailed to take place this week, Mr Johnson went into self-isolation on Sunday evening after a member of parliament he met with was diagnosed with coronavirus.

Mr Farage went on to warn that the promises made during the Brexit campaign are in “peril” because the “leavers are leaving Downing Street”.

“We’re going through the biggest peacetime economic crisis in history, the clock is running down to the end of Brexit negotiations and yet the girls and boys in Westminster are all busy playing games all trying to stab each other in the back,” Farage said.

He noted that while the main focus of the negotiations with the European Union has focussed on fishing rights and the so-called “level playing field” demands from Brussels, there has been a lack of focus on one of the driving issues of the Leave campaign, to get control of migration.

Farage predicted that the final deal with the European Union will do little to restrict the free movement of people, saying: “unless we get the right Brexit deal nothing will change.”

“If you add to that the likelihood that the duffer, Joe Biden is going to become the next U.S. president and has said already that our relationship with the USA will depend on how happy Brussels and Dublin are with the deal, you can see right now that Brexit is in great peril,” Farage noted.

The arch-Brexiteer said that while he expects there to be further fights over Brexit over the coming years, he is “not going to stand by and just let this thing be just run into the long grass for us not to get the benefits that Brexit should give us. I won’t do that without standing up and fighting.”

“If I’m wrong then tell me at the end of December I’m an idiot and I should have trusted Boris all the way through but I’ll make this prediction right: now Brexit is in peril,” he concluded.

Follow Kurt Zindulka on Twitter here: @KurtZindulka