Robert Lindsay takes on the central role of Rupert Bull...

What appealed to you about this show?

The moment I read it, I thought it was fantastic. The wackiness of it immediately grabbed me. It has a wonderfully absurd sense of humour. I said to the writers, "What's the logic of this situation?" They replied, "There isn't any," and I said, "Fine, I'm with you."

Bull takes risks, but ultimately it's just really funny.

Please outline your character for us...

Rupert is a great character. He's a mixture of a lot of antique dealers. He has a slight effeminacy about him, but in the end he's just a con man who doesn't have the faintest idea what he's talking about. He doesn't have a clue, for instance, how much Fabergé eggs cost.

The great thing is, you know Rupert is always going to be caught out in the end. In that, he's like Ben in My Family, who was a pompous, alcoholic dentist who always got his comeuppance. These sorts of characters are great. They're flawed, pretentious and will inevitably be caught short.

You have this marvellously dapper look, complete with natty suit and moustache. Is that helpful for this role?

Definitely. This look really helps me get into character. For instance, a moustache is always useful. I can play with it, especially in Rupert's more manipulative moments.

How would you describe Rupert's relationship with Beverley, played by Maureen Lipman?

She was a presenter on The Antiques Roadshow but she was fired for some misdemeanour. Rupert then employs her in his shop, which she completely resents because he clearly knows nothing about antiques. She becomes a malicious sort of Cruella de Vil figure, making his life hell. Now she spends all her time undermining Rupert and making sure he gets caught out.

Ultimately she's looking out for him and the shop - she just enjoys making him squirm.

How have you found it working with Maureen?

She's wonderful. She's really taken on the mantle of the character. Beverley sits at her desk all day, smoking and scheming and trying as hard as possible to do no work, while actually keeping the whole enterprise afloat. It's a tremendous performance.

So you really relish comic roles?

Absolutely. Even when I played Hamlet and Richard III, I was always seeking the humour in the part. Humour is about making contact with people. You hear an audience laugh and you know they're listening.

When I played Richard III, I thought, "I'm not going to be evil and make people go 'urgh!' I'm going to make him a stand-up." I chose to do it that way. If you turn to the audience and conspiratorially say to them, "I'm going to play the villain because that's the only way I can get on," they lap it up.

One critic said that my Richard III reminded him of Ken Dodd - that was the biggest compliment I could have had.

Do you see a difference between playing comedy and tragedy?

No. When I played Wolfie in Citizen Smith, the producer said to me, "I can't work out if you're an actor or a comedian." And I replied, "It's the same thing, isn't it?" Ian McKellen is a great classical actor, but he's also one of the funniest men around - his comic timing is immaculate. Michael Gambon is the same - he can shine in The Norman Conquests just as much as in A View from the Bridge. Humour is a way into people's souls because you release something within them. If you use humour, you can really hit a nerve.

Finally, what impression of Rupert do you think viewers will be left with?

He's every dodgy antiques dealer you've ever seen. Would you buy a second-hand car from this man, let alone a second-hand clock or Fabergé egg? No, you would not!