Mason - played by Philip Voss - is also back for Series 2 of Vicious...

What do you think is key to the success of Vicious?

The writing, for a start. It's very funny. And you'd be lucky to get a better cast. Two knights, plus Frances de le Tour and Marcia Warren, with a brilliant newcomer from Games Of Thrones.

I had worked with Ian before on the stage in the 80's, and Derek I'd worked with in rep in the early 60's. We're all really friendly with each other, we all get on terribly well.

What's it like filming in front of a live studio audience?

It's lovely for me because I don't do a lot of television. I have much less to do than anyone else but it suits me very much because we have lots of rehearsal time.

But then we have the live reaction from the audience which is terrific, it really does lift you.

I only had two lines in one episode but the reaction to that final line - which I won't give away! - was so huge, it gave me euphoria. I was smiling all the way home.

Ian and Derek absolutely thrive on the audience. They chat to them in between scenes and Ian shows them old pictures of he and Derek at Cambridge together.

How important is the relationship between actors?

Very, particularly for me with Marcia. I feel like I've known her all my life, but I've never actually worked with her before.

She's absolutely adorable, we get on like a house on fire. I don't think there's any tension between any actor in the group, but certainly not between us.

It's so easy between us, I've never known it quite so warm. It's hell if actors don't get on, there's not a trace of that here.

What impact has this programme had on people's attitude towards gay people on television?

We are making huge strides, but there is still homophobia which is still engrained.

My admiration for Ian and Derek to play Freddie and Stuart as they do is boundless, because it's full on and the audience can either accept it, or not.

When I think of the help that Vicious might offer any teenager going through terrible doubts about their sexuality, it's fantastic that we may be able to help a little.

But of course there's many more shows than just us that are doing the same. I'm a product of the 1950's which were appalling, you just felt you were alone.

Do you think Vicious is, despite its name, a warm sitcom?

Yes, definitely. The basis of Stuart and Freddie's relationship is love, and there is love throughout.

All the characters are dealt with very sympathetically and humanly, I would it hate it if it was just nasty.

And that wouldn't happen anyway, I remember in the first series delivering a line and the Director said to me, 'I know it's called Vicious, but no need to lay it on with a trowel. That's not what we are about.'