David Cameron breaks his post-resignation silence

Three years after his career-defining, and ending, defeat in the 2016 referendum on the U.K.'s membership in European Union, Cameron sat down with Andrew Billen of the Times of London ahead of the release of his memoir next week.

Why it matters: Cameron's successor, Theresa May, was swallowed up by Brexit chaos and replaced last month by Boris Johnson — Cameron's rival in the referendum campaign. In the interview, Cameron claims Johnson supported the "Leave" side out of personal ambition, left "the truth at home" during the campaign and never expected to win. He also says a second referendum may be needed to resolve the Brexit question.

The backstory: With British politics now defined almost entirely by Brexit, Cameron has little natural support.

• "Remainers" loath him for calling the referendum, while "Leavers" distrust him for leading the opposing campaign.
• Anger has also bubbled up over the idea that Cameron fled the scene after Brexit and left the rest of the country to deal with the consequences.
• Cameron tells Billen he understands that anger, but insists a referendum was "inevitable" after repeated promises.

Cameron says the result, and his resignation, left him "hugely depressed."

"Every single day I think about it, the referendum and the fact that we lost and the consequences and the things that could have been done differently, and I worry desperately about what is going to happen next."

Other key points:

• Cameron accuses fellow Conservatives of crossing a red line in their attacks on him during the campaign. He writes in the book that Johnson and Michael Gove, his former cabinet minister and personal friend, behaved "appallingly."
• Cameron says he's exchanged a few texts with Johnson. He also notes that Johnson sent him a text the day he resigned — an apology for not having been "in touch."
• He says he texted "frequently" with May, commiserating about the "maddening" steps hardliners like Johnson had taken to derail her Brexit plan (which he says he would have voted for).

What to watch: Cameron says he doesn't support the tactics Johnson has used — suspending Parliament and expelling members who voted against him. He opposes a "no-deal" Brexit and says a second referendum might be needed, "because we're stuck."

Flashback: Cameron, who served from 2010-2016, allows himself a bit of speculation about what might have been.

• He defends his "economic rescue job" after the 2008 recession and his steps on the environment.
• He argues that if he'd only been able to reform and then reaffirm the U.K.'s membership in the EU through a referendum victory, it would have been "a boon for Britain."
• If that had happened, he might still be in office. And his legacy might not start and end with the worst defeat of his career.