'What will people think? I don't care any more'

At 90, Alan Bennett has written a sex-fuelled novella set in a home for the elderly. He talks about mourning Maggie Smith, turning down a knighthood and what he makes of the new UK prime minister

- Mark Lawson

Alan Bennett never expected to be writing in his 90s, with a novella published this month and a film in post-production. There was a time when he didn't expect to reach 70. In 1997, a cancerous growth was found in his colon that had already begun to spread. "The surgeon didn't think I'd got a chance, really," recalls Bennett, 27 years on. "So yes, it is a slight surprise that I'm 90."

He attributes these bonus decades to two younger men: his partner, the magazine journalist Rupert Thomas, 58, and the director Nicholas Hytner, 68, with whom he has worked on 11 theatre and screen projects. "It was luck that I met Rupert - over a shared taste in paintings, really - and also that I met Nick, more or less at the same time, around 30 years ago. It's been the best period of my life. Without Rupert and Nick, I'd be nothing, I think."

Although Bennett and Hytner had already collaborated on The Madness of George III, Bennett dates his creative renaissance to The History Boys (2004), his most commercially and critically successful work, about a group of Leeds sixth formers and their eccentric teacher, Hector. "I'd long given up hope of writing anything really fresh, but it was so enjoyable. The actors treated me as part of the cast. The first preview was my 70th birthday and I couldn't believe I was still going at that age."

Twenty birthdays later, he still is. The only concession to the decades is that he apologises for not getting up from the sofa to greet me at his north London home, where Kate, a friend of the couple, is on hand while Rupert is at work.

"This is a recent development," Bennett explains. "I've fallen once and that totally altered Rupert's approach. He doesn't like to leave me on my own for long, and so we have people who come in." Health-wise, he says, "the main problem is I can only walk a short distance. Since I had cancer, I've been regularly in hospital one way and another for other things."