Johnson and Cameron rivalry ‘so fierce they battled over who could walk faster’

In a new book charting 13 years of Conservative rule, Will Walden, Mr Johnson’s former communications chief when he was London mayor, revealed even the most mundane activities would become a competition.

He said: “Boris would walk faster and then Cameron would walk faster and then Boris would walk faster.

“It would get to the point where you were practically running.

“And it was unsaid. It was basically willy-waving.”

The Right to Rule, by Ben Riley-Smith said the former Newsnight presenter Jeremy Paxman tried to rile Mr Johnson by questioning whether he felt intellectually inferior to Mr Cameron, who received a first-class degree at Oxford compared to his upper second class.

Did it rankle? “It would if it wasn’t that his first was in PPE” rather than Classics.

Mr Cameron would have “wargame” strategies to deal with the then mayor’s party conference speeches, which always stole the attention from him when he was prime minister.

“It was dubbed ‘Boris handling day’,” the book says

The book also reveals Mr Johnson uses a strategy from Dodgeball, a 2004 sports comedy when he is in a scrape.

“When in a tight political spot, Johnson would repeat the ‘five Ds’” – the advice given to players, it say.

“Dodge, duck, dip, dive and dodge,” it explains.