Nigel Farage, the leader of the Brexit Party, said the prime minister would lose a general election if he rejected a “non-aggression” agreement

Allies of the prime minister attacked Nigel Farage yesterday and said that he should never be allowed “anywhere near government” as Boris Johnson appeared to kill off the Brexit Party leader’s hopes of an electoral pact.

A senior Conservative source added that Mr Farage, the former Ukip leader, was not a “fit and proper” person.

Mr Farage had told the prime minister that the Brexit Party could be his best friend or his worst enemy and that the Conservatives would lose a general election if he rejected a “non-aggression” agreement.

However, a spokesman for the prime minister said: “The PM will not be doing a deal with Nigel Farage.”

The “not a fit and proper person” charge was also levelled by the senior Conservative source