Boris Johnson was dismissed as an “irrelevant and offensive person” by a speaker at the Tory conference, to the delight of many delegates.

Businessman and peer Digby Jones criticised the former foreign secretary for reported comments he had made over the summer when asked about industry concerns around Brexit.

Mr Johnson was said to have uttered a four letter expletive when asked about businesses’ Brexit concerns at a diplomatic dinner.

Theresa May at the Conservative Party conference
Theresa May, centre back, at the Conservative Party conference (Stefan Rousseau/PA)

The cross-bench peer, whose speech was watched by the Prime Minister, said: “Business is so important that when I heard a former foreign secretary f-business, it showed him up for the irrelevant and offensive person he really is.”

Lord Jones, who is a former Labour transport minister, also urged the Tories to stop tribal battles and unify against the “threat” of Jeremy Corbyn reaching Downing Street.

He said: “You’ve got to unify and stop it because you’ve got a far greater threat than Brexit coming down the path.

“That is that Jeremy Corbyn is to wealth creation what Diane Abbott is to mathematics.”

He went on to warn that if Labour came to power there would be a “flight of capital and talent”, adding: “This isn’t my country if that lot get into power.”

Earlier, party chairman Brandon Lewis issued a similar warning, telling delegates that Mr Corbyn was the “enemy”.

He said: “We must engage in this battle and turn our fire on the enemy, Jeremy Corbyn and his dangerous hard-left ideas.

“The choice in British politics has rarely been so important or so clear.

“It’s between a Conservative Party, the party of the union, that wants to spread opportunity and bring people together and Jeremy Corbyn, a man who sanctions and tolerates division and hate.”

Mr Lewis also turned his gaze inward and warned delegates that the party needed to change and needed to attract more people from diverse backgrounds.

To ensure this he announced the party would be establishing a “dedicated mentoring fund” to support those who were under-represented.

He said: “It is a fund to provide guidance and training to help them pursue a life in public service, and to encourage more people from diverse backgrounds to stand for Parliament, become MPs and help us truly represent the face of modern Britain.

“For if we don’t make these changes, this party – the oldest political party in the world – faces a challenging future.”