Boris Johnson was advised by his campaign manager not to back Brexit, according to one of the authors of a book on the UK's EU referendum.
Tim Shipman said that Ben Wallace, who was underpinning the campaign to elevate Johnson to the Tory leadership, told Johnson he should vote Remain so as not to align himself with the "clowns" supporting Brexit.
Shipman also told Julia Hartley-Brewer that, in the days before he came out for Leave, Johnson made a pro-EU article "deliberately bad" to convince himself Brexit was the right way to go.
Johnson has defended writing the article just two days before he publically backed Leave, claiming it was "semi-parodic". Shipman said the article, which has now been published in the Sunday Times, "would have been much better" had Johnson already decided to back Remain.
Listen to the full interview above