Johnson is third prime minister in six years to be brought down by Tory infighting

David Cameron, Theresa May and Boris Johnson have all been brought down by Tory infighting (Stefan Rousseau/PA)

Boris Johnson is the third Conservative prime minister to be brought down by Tory infighting in the space of six years.

A split over Europe ultimately led to David Cameron losing his Brexit gamble and resigning, while Theresa May failed to unite her warring MPs over plans to deliver on the outcome of the referendum. In Mr Johnson’s case, his own leadership caused a rift in the party.