(Photo: Getty Images)

If you were to make a list of the greatest ever The Graham Norton Show guests, Miriam Margolyes would probably appear near the top. The Harry Potter and Call the Midwife actress has appeared on the show seven times, and made us howl with laughter on each occasion.

Thanks to these and other TV appearances in recent years, Margolyes has perhaps gained a reputation for being a bit of a potty-mouth. However, in a new interview with The Guardian, the 81-year-old has insisted that this isn't actually the case.

"I don’t like filthy jokes," she said when asked to tell one. "People have this idea that I’m a walking cesspit. I think it’s quite unfair. I take great care in the words I use and when I use swear words, I mean to use them. I don't like a loose use of filth. I like a precise use of filth."

She also addressed a now-infamous BBC Radio 4 interview from last October in which she accidentally dropped an "F-bomb" while talking about the British chancellor, Jeremy Hunt. "I gave myself a lot of stick because it was totally unintentional," she said. "I did not know that the microphone was on. I was shaking all the way home in the taxi. I was really upset because Radio 4 is a holy temple."

For a reminder of Margolyes' straight-shooting style, check out this classic clip where she brands Mamma Mia! "a dreadful film" – in front of Mamma Mia! star Dominic Cooper.

Do you enjoy Miriam Margolyes' visits to The Graham Norton Show?