Mark Thomas

But that's hardly surprising - after all, Mark is almost as well known as a political activist as a stand-up comedian. These days you are just as likely to see his face on the news - taking part in a political demo - as on a comedy show.

He started his near sell-out current tour, Mark Thomas: A Minor Celebrity Discusses War Crimes, in mid January. It continues until mid June.

It seems a little bizarre that the war with Iraq - one of the subjects of Mark's show - could begin and end in less time than it will take him to complete his tour.

"The issue hasn't gone away," says Mark of the war ending.

"You've still got an inordinate amount of civilians that have been killed, you've still got an inordinate amount of Iraqi conscripts that have been killed, you've still found no chemical weapons and we've spent billions on this war.

"You've got nothing that has prevented terror at all. In fact, as people were saying from the beginning, this is going to be the biggest recruitment campaign for al-Qaida. There's still masses to talk about."

If people are worried that Mark's live performances will just turn into lectures rather than a political stand-up comedy show, he assures them that they needn't worry.

"The live show's vastly different from the telly shows because you've only got 23 minutes on telly. You've got to tell the story and build in the right to reply of the people you're talking about," he says, explaining why his TV shows aren't packed with gags.

"The number of times we've left gags on the cutting room floor breaks my heart."

But Mark admits that as he gets older he becomes more political.

"When I was growing up I was really into punk so I was into anti-state, anti-nuclear stuff and anarchist ideas and then those kind of changed for a bit and I thought 'no, I was right first time round'. I get less mellow as I get older, which I like. I like that feeling of thinking I'm supposed to settle down and be quiet and be safe. I'm not supposed to be running round corporate headquarters, trying to shut them down."

He's not all talk either. His campaigns have succeeded and the one he is proudest of is the Ilisi Dam Campaign, which opposed the building of a dam in Turkey that would have resulted in a huge number of Kurds being forced out of their homes.

"I was a campaign founder and director. I did a couple of shows about it and because of the head of steam building up over it a group of us got together. We ran the campaign for three years," he explains.

"In the end they cancelled the dam. It was a huge deal, affecting up to 70 or 80 thousand Kurds, to beat seven multinationals, seven governments and one torturing state plus a Swiss bank - that's not bad going!"

Mark is a very inspirational speaker, but what effect would he like his words and the campaigns he's involved with to have on the world?

"If we could just get people to take responsibility for the fact that they might have a part to play in the activities of this planet. If we could just get the West to acknowledge that yes, we have a role in the misery and suffering of others, we'll have taken a major, fundamental step forward," he says passionately.

"Getting to that point will be a minor miracle, God knows what happens afterwards. Whether we'll all be led to Shangri-La or the corporations will fall or there'll be a backlash, I have no idea. Just getting people to admit that they have a part in the world and have some responsibility is a major challenge."

And does Mark have any tricks up his sleeve to make this wish come true?

"What I've got planned in the next couple of weeks is to release the ravens from the Tower of London - the rest will all fall into place."

Mark Thomas will be at the Theatre Royal Winchester on Tuesday. An extra date has been added on June 17. Tickets: £13.50. Box office: 01962 840440.