IF YOU need any convincing that Sandi Toksvig is a national treasure, you just have to listen to her talking about renewing her wedding vows in an event attended by thousands of fans at the Royal Festival Hall in London.

“My wife and I renewed our wedding vows on the stage,” explains the Danish-born comedian, presenter and actor. “It was a small gathering, a few family – and a thousand of my close friends. It was held on the day that same sex marriages were made legal.

“It was astonishing. I invited 150 family and friends, and let it be known to the general public that if anybody wanted to come, they were most welcome.

“The hall was full. There were literally thousands of people. It was every kind of person you could possibly imagine. It was very jolly. The only drawback was that there wasn’t enough cake!”

It’s hard to find anyone who doesn’t like Sandi Toksvig and in a nod to her unofficial status, her latest tour is called National Trevor.

After a spell making TV shows such as The Great British Bake Off and QI, Sandi can’t wait to come face-to-face with her audience again in a show that will feature a Q&A and lots of jokes, including funny facts.

“I’m endlessly interested in things,” says the 60-year-old. “I think detail is terribly funny. Did you know that the glue on Israeli postage stamps is Kosher?”

National Trevor will also showcase a general knowledge quiz, although she says: “I don’t know if you want to win it, because then you have to come up on stage and talk to me all about your life!”

It’s the audience interaction that Sandi is most looking forward to, adding: “I can’t wait to get out there. The best bit is not me talking to them - it’s them talking to me. Me talking? Not so interesting. Them talking? Very interesting!

“You never quite know what is going to happen.‎ The unexpected stuff is always the most enjoyable part. The most unexpected thing that ever happened in a show took place during a Q& A in Bradford. A woman asked me what my bra size was. I couldn’t remember, so she had to come up on stage and have a look!”

That title, National Trevor,  also comes from a witty exchange. Sandi explains: “One day, a friend of mine was being extremely rude to me‎. A lot of my friends are - I encourage it! So in the middle of this argument, I said to her ‘don’t you know I’m a national treasure?’ and she replied ‘you’re a national Trevor?’ Then her husband said ‘who’s been calling her Trevor?’ Now they call me Trevor.

“So that's why I gave the show this title. I’m going round the country looking for all the National Trevors. I’m celebrating people.”

Sandi Toksvig’s National Trevor tour reaches G Live in Guildford on Wednesday (23 January).