In his first novel, Head of State: A Political Entertainment, British author Marr imagines how the death of a political leader on the eve of a major referendum might play out.

Where did the idea for the book come from?

This book has been bubbling for a very long time. During the John Major years, Lord Chadlington was working in #10, and one day noticed that the prime minister had come down from his flat looking so ill that Chadlington thought he was about to die. He then asked himself what would happen if the prime minister died while in office, in the middle of a major crisis—for how long could the death be hidden? Lord Chadlington is not himself a writer, but thought it would make the basis of a good novel. Many years later—about two years ago—he came to me with the idea, and I started to work on it. I then had a very major stroke, and gave myself the job of writing the novel as something to distract me during the first year of my recovery.

Could the novel have worked with a Washington, D.C., setting?

Because of the greater openness of the White House, and of American political culture generally, it would be harder to hide the death of a president from the American public, even for a few days. That said, many of the tricks used are completely transferable to Washington: and so, I suspect, is the key point—that the media and public often collude in their own deception!

Do you believe the U.K. is as divided regarding the E.U., as in your vision of political events in 2017?

Yes, Britain is deeply divided over Europe, and I think the referendum I’m writing about is likely to happen, within a few years. It’s become an existential issue in British politics, and even former prime minister John Major, a Europhile Conservative, now says that there would be a 50-50 chance of the U.K. leaving the E.U. in such a referendum.

You had a book launch hosted by Prime Minister Cameron. How have the politicians you know reacted to the book?

It was sporting of David Cameron to do that. He hadn’t read the book, and mistakenly said he thought it was about the assassination of the prime minister. By and large, politicians have complained that my book is too extreme: I then have to sit them down and patiently explain that it has been carefully researched and is all completely plausible.

What was the hardest part to write?

In London we have something called “the bad sex awards,” a prize given for the most cringe-worthy or implausible sex scene in a work of fiction. I missed making the shortlist, but apparently only just.