Boris Johnson claims principle drove his Brexit decision, but cabinet rivals say it was ambition

A new BBC documentary examining the 2016 Brexit referendum has surfaced sharply divergent explanations for Boris Johnson's decision to back the Leave campaign, with Johnson claiming principle guided his choice while former Prime Minister David Cameron and Chancellor George Osborne describe it as a strategic bid for higher office.

The Competing Narratives

In "Brexit: A Very British Civil War," a two-part documentary directed by Max Stern and veteran documentarian Norma Percy, Johnson addresses allegations head-on. "Everybody says I did this in order to be PM," Johnson states in the film. "I would have become prime minister anyway." The assertion carries particular weight given that, at the time of his February 2016 decision, Johnson held the position of Mayor of London while simultaneously serving as Member of Parliament for Uxbridge.

Cameron and Osborne present a markedly different interpretation. According to the documentary, Cameron had attempted to secure Johnson's support for Remain by offering him a cabinet position during a game of tennis at Winfield House, the residence of the US ambassador near Regent's Park. Cameron explains in the film: "I didn't say which job it was, I said: 'Be in no doubt, defence is a top five job, for instance…' I wanted him to understand that I valued his contribution, that he would be a major part of the government, going forward." Osborne, with characteristic brevity, encapsulates his interpretation of Johnson's motivations: "It was Game of Thrones."

Documentary Approach and Revelations

The documentary draws on interviews with major figures from the referendum period, including Nigel Farage, Jeremy Corbyn, Gordon Brown, and Michael Gove, though Dominic Cummings notably declined to participate. Percy has built her reputation on accessing high-profile subjects for documentary work, having previously covered the Northern Ireland peace process and Putin's Russia. The film concentrates on events spanning from the 2015 general election through the June 2016 referendum vote. Rather than adopting a somber tone, the documentary employs attention-grabbing anecdotes and bombast, leading one major publication to observe that "no documentary about Brexit should be this much of a hoot." Farage, for instance, recounts that Vote Leave leaders "didn't really want to win," a claim that underscores the often-chaotic nature of the Leave campaign's internal dynamics.

The documentary also examines the defective approach taken by leaders of the two principal political parties. According to the sources, David Cameron's Remain strategy and Jeremy Corbyn's comparatively muted Labour support for staying in the EU both contributed significantly to the referendum's outcome, which saw 48 percent vote to remain while 52 percent backed Leave.