Boris Johnson reportedly left ex-Conservative leader Sir Iain Duncan Smith banging on the front door while he hid in his bedroom to avoid talking about Brexit, days before he became PM.

The former Mayor of London and his advisers pretended not to be home despite IDS chairing Mr Johnson's leadership campaign, according to a new book by ex-Downing Street spin doctor Peter Cardwell.

Mr Cardwell was sacked in February, having spent years rubbing shoulders with numerous Cabinet Ministers.

His book The Secret Life of Special Advisers recalls the "farcical scene" in the days before Mr Johnson officially took over from predecessor Theresa May.

Former Conservative Party leader Iain Duncan Smith

Former Work and Pensions Secretary, Sir Iain was brought in by Mr Johnson to help convince Tory MPs who were unconvinced about his stance on Brexit.

“IDS attempted to ring him several times to suggest they have a strategy discussion at the campaign’s headquarters at the home of Andrew Griffith, a Sky executive who later worked in Downing Street and became an MP in December 2019," Mr Cardwell recounts in the book.

Johnson and Duncan Smith at an event in 2018

However, Mr Johnson "ignored both calls and texts until finally IDS texted to say he was on his way round".

The book continues: "With IDS en route, Boris quickly ordered his entire team to race up the stairs to the first floor of the house and, well, hide from their alleged campaign chairman as he rapped on the door of the building, demanding to be let in.

"Eventually, IDS gave up knocking on the door and ringing the bell, and the Johnson team gingerly made their way downstairs again to their makeshift offices to resume their work."

A senior Conservative Party source told The Sun: "It seems this book is more a work of fiction than an autobiography but we wish Peter well."

While the newspaper also reports various Downing Street names mentioned as those allegedly hiding with Mr Johnson have also disputed Mr Cardwell's account.

Though he told The Sun "that's what we in the trade would describe as not a denial".

IDS reportedly declined to comment when approached.