Maureen Lipman plays the chain-smoking Beverley Bull...

What attracted you to Bull?

I got the script out of the blue, and I thought, "I'll have some of that!" There's a lovely surreal quality to the writing. It's also a very physical comedy, and I really like doing slapstick. Gareth and John-Luke are very talented young writers, and I'm in love with talent.

What else have you enjoyed about working on this show?

The director, Simon Gibney, is really good. He's very clever and very calm. He also likes input from the actors - which is great at my age. It's very easy for a director to make you feel like you're still in pupillage. Neither Robert nor I have very much time for that approach.

How would you describe your character?

She's a bit of a monster, and monsters are always good fun to play! Beverley is lazy, chainsmoking, manipulative - all things that I do not find a stretch! I like the idea of someone who sits in the background and every now and again drops a pearl into proceedings. I'm not saying it's Maggie Smith, but it's great fun to be lurking until the killer line arrives and then pounce!

She's bitter because she was a presenter on The Antiques Roadshow, but it all went pearshaped. Now she's stuck in Rupert's shop, and she enjoys manipulating him and his idiotic schemes. She's always undercutting and teasing him - but usually saves the day. Every time he tries something new, she tries to drop him in it and then rescues him from himself. She definitely doesn't want any customers. She just wants to sit there reading books and smoking cigarettes.

Can you expand on the joy of playing monsters...

The devil gets all the best tunes! If you're playing the good girl in Dracula, it's boring. It's much better to play the bad girl. It's much more fun to play Medusa than her good sister. That applies to comedy, too. If you look at a list of great comedy characters - from Andy Capp and Hylda Baker to Hyacinth Bucket, Alf Garnett and Victor Meldrew - they're all loveable villains.

Look at Curb Your Enthusiasm, which is a great favourite of mine. After my husband died, the kids and I snuggled up in a duvet and watched Curb almost every day, laughter helped the grief. That show touches on something klutzy in all of us. You look at Larry David, the lead character who is a monster, and think, "There but for the grace of God, go I." Shows like that give us a greater understanding of human foibles and the human condition.

There has been a trend for PC comedy in recent times. What do you think of that?

Political correctness is the death of comedy because someone has to be superior and someone has to be inferior. You have to have someone to look down on. In Canada, for example, the people from Newfoundland are the butt of the jokes. Without an underdog, there's no dog and no comedy. In Britain, we're particularly good at pricking that bubble.

You have great chemistry with Robert Lindsay on screen. Where does that come from?

We're both from the same background. We were both working-class actors who were very fortunate to emerge at a time when you didn't have to have come from a Received Pronunciation background because the path had been paved by actors like Albert Finney and Tom Courtenay. Therefore it didn't matter if you talked like we talked and it didn't matter if you hadn't been to the Joyce Carey School of Speech. Also, Robert and I have both been brought up to be very professional. We have both done a lot of theatre and we both have a history in comedy.

You've done a lot of great comic roles over the years. Do you especially enjoy performing comedy?

I love it. But it's very difficult. It's completely technical, but you have to make it look like it isn't. If you look like you're trying to get a laugh, you're dead. Also, with a comedy, everyone is an expert. Everyone recognises comic situations, but no one is going to argue with your interpretation in a serious drama because they don't know what it's like to be visited by the ghost of your murdered father.

What do you hope viewers will get from Bull?

I hope they really enjoy it. It's zany and off-the-wall, and the writing's really good. There is a character in this show for everyone to identify with. But I hope above all that audiences laugh. I think they will.