Charlotte Rampling will be 60 next year and is only too happy to admit it: “I used to knock one or two years off, but not any more. Why should I?” And that’s not all. “I’m a grandmother three times over and very proud of it,” she said. “Two of them live in London and one in Paris. It’s absolutely lovely to be able to cuddle them as babies.”

The British-born actress, who first made her name more than 30 years ago with extraordinary parts in films such as The Damned and The Night Porter, is completely open about her age and looks. Not that this grandmother has anything to hide.

Slim and glamorous when I met her last week in Cannes, where she unveiled her latest film, Lemming, Rampling was wearing a stylish dark grey suit and black shoes and looking gorgeous.

I had last seen her in the fabled French resort two years ago when Swimming Pool, in which she played a rather old maid-ish (very much cast against type) English novelist, was shown. Now she seems calmer and happier.

“I’m a much more mellow person these days,” she said as she lit up one of her favourite small cigars.

A pot of English tea was served, a reminder that although she lives in France she is a colonel’s daughter from the home counties.

While we were talking she noticed a boat moored nearby in Cannes harbour. It was called Gogo. That is what Roman, her three-year-old grandson, calls her.

“It’s so sweet, isn’t it?” she said. “I don’t know why he calls me that; maybe because it’s difficult for him to say grandma and it comes out as Gogo.”

I told her about the very different reaction I received when I raised the question of ageing in an interview with Marianne Faithfull, another celebrity grandmother, a month ago.

The singer, like Rampling, emerged from the home counties middle class of the 1950s to become a prominent beauty on the Swinging Sixties London scene. She, too, will be 60 next year and, like Rampling, now lives mainly in Paris.

But, unlike the actress, Faithfull refused to discuss her grandchildren. She told me that her manager, who is also her lover, said that it would be bad for her career to discuss such matters.

Faithfull was clearly worried about her looks and was seeing a psychiatrist to cope with “having once been so young and beautiful”.

Rampling smiled wryly when she heard this and then shot me a stern look from those ice-blue piercing eyes: “I’ll bet you wrote it up that she didn’t want to discuss her grandchildren. And made a point about it, too.” Well, er, yes I did.