Your debut novel, HHhH, deals with the assassination of the Nazi leader Reinhard Heydrich. When did you first become interested in him?

The first time I heard about him was from my father, who was a history teacher. Then later, when I was sent to Slovakia for my military service, I remembered the story told me by my father, so I searched for more details about it. And an amazing story emerged.

This is not a straightforwardly historical novel. You place yourself squarely in the narrative.

To make a fiction with Heydrich’s story, to make it up, I wasn’t interested in that. As a writer, I felt it was best to stay as close to the truth as possible. The most natural way to do that was a conversation with the reader. As a reader, I like it when the author talks to me. Like when Kundera does – I love that.

Kundera’s novels are not quite novels and not quite essays. Is that what you like about them?

Yes, I like the mélange des genres. That’s why I prefer Shakespeare to Racine or Corneille, for example.

It’s often said that novels give us access to other consciousnesses. Are you claiming to give us special insight into Heydrich’s motives?

No. When I read Jonathan Littell’s The Kindly Ones I don’t get any access to the consciousness of a Nazi; I just have access to the mind of Jonathan Littell. To claim that you will get some truth about the mind of anyone, this, for me, is just a lie. When I read War and Peace, I like all the scenes in which Tolstoy is in the mind of Napoleon, but I appreciate it as a game. It has nothing to do with the truth.

In your novel, you write that Littell’s protagonist more closely resembles Michel Houellebecq than a Nazi functionary.

The guy’s sex life is miserable. He’s very clever, very nihilistic, a kind of philosopher. The problem with The Kindly Ones is that it’s always talking about our time, but not that time [the Second World War]. Now that needn’t be a problem, but the book wasn’t sold like that in France. People were saying it’s the greatest ever book about the Second World War. What disturbed me is that when people said that, they were including works of history as well as novels. Some people said, “If you want to understand [the Eastern Front of] the Second World War, read The Kindly Ones.” I disagree.

Were you already working on HHhH when Littell’s novel came out?

Yes, I’d been working on it for four years. I was disturbed when The Kindly Ones came out. Disturbed because I felt we were working on the same subject. I felt jealous of the book’s success, I guess, but more importantly, I felt Littell was doing something I didn’t want to do. His method was not mine.

He has claimed that there is such a thing as “novelistic truth”. I suspect you’d have little time for that idea.

It’s bullshit. Novelists give themselves too much importance. I love novels, I love fiction, but I don’t like it when fiction claims to be more true than the truth. Truth is a big word that carries many meanings. Truth as a fact about the weather today? I’m interested in that. But truth as something metaphysical? I’m not interested in it. And the idea of “novelistic truth” has something metaphysical about it. But according to Kundera, the novel is the country of doubt and of questioning. When you start to speak about “novelistic truth”, you’re getting closer to religion.

I gather Nicolas Sarkozy phoned you to say how much he liked your book.

He said he liked my book and we talked on the phone for five minutes. He invited me for lunch but I declined because I don’t like his politics. I’m on the left, but that doesn’t mean I can’t talk with someone from the right. I could eat lunch with Villepin, maybe Chirac, but Sarkozy was too harsh, too hard on the weak.

You recently followed François Hollande on the campaign trail for another book. How did that come about?

I met him in June 2011, then got the idea for the book after watching The West Wing.

Laurent Binet’s “HHhH” is published by Harvill Secker (£16.99)