Another stunt highlighted how difficult it is to view art which, in return for tax exemptions, some stately home owners are meant to display publicly.
His programme, The Mark Thomas Product, exposes hypocrisy and wrong-doing in high places with a mix of comedy, stunts and investigative journalism.
During the course of the series, he has managed to get Indonesian military chiefs to admit on camera that their government tortured dissenters to "protect the security of our society".
He also turned up at a Nestlé promotional fun day dressed as a huge teddy bear, and then produced a huge ghetto-blaster playing Zimbabwe's health minister making serious allegations about Nestlé's baby-milk marketing methods.
Another stunt highlighted how difficult it is to view art which, in return for tax exemptions, some stately home owners are meant to display publicly.
He tried to take groups of people to stately homes to see the works of art.
The artworks included a Gainsborough owned by Sir Evelyn de Rothschild, who later took that and 300 other works off the list and paid the tax.
The programme, which has so far completed four series for Channel 4, has delighted television audiences, but leaves the political world unsettled.
He is currently at the centre of an alleged Whitehall smear campaign, and has accused the government of failing its pledge to be "whiter than white".
Thomas was named in an e-mail sent by an unnamed civil servant saying Trade and Industry minister Richard Caborn wanted "background/dirt on him in order to rubbish him".
The Department for Trade and Industry says the official involved, who has been reprimanded, misinterpreted Mr Caborn's request for background information.
'Pro-choice parents'
Thomas's interest in politics began early, when he witnessed his parents taking direct action over their beliefs.
He was born in 1963. His father was a builder and lay preacher at Clapham's Nazarene Church and his mother was a midwife.
He won a scholarship to Christ's Hospital public school and went on to study at Bretton Hall drama college in Wakefield.
His parents' political views differed somewhat from his own, however.
In an interview last December with the Sunday Herald, he described how his pro-Choice parents would drive past the placard-waving pro-Lifers assembled outside Brixton clinics, "then dad would shout the most foul-mouthed abuse".
'Escape'
''Dad was a working-class Thatcherite before Thatcher, who believed you have to get out there and help yourself," he added.
Unhappy at being sent away from home to school, Thomas described how he bunked off, usually to the school theatre.
"It was a way of escaping, of entering another world," he said.
He began performing his own sketches and shows, encouraged by his drama teacher.
Thomas' interest in drama was piqued by his appetite for politics, and by the time he became a student, he was doing benefit shows for the miners' strike and became a picket-line activist.
'No Nestlé'
After college he worked for his father by day and did stand-up by night.
He then moved into full-time comedy, doing stand-up tours of the UK, before his television series took off.
But even when he is not working, Thomas is always on the lookout to prove his point.
He described how, on a recent trip to Tate Modern with his son Charlie, they stuck pictures of the five-year-old's art up on the walls, and Charlie innocently asked: "'Do you think anyone will buy them?"
Thomas added that he tried not to "dump" his politics on his children, but he would not go as far as to allow Nestlé's breakfast cereal in their kitchen.
The Mark Thomas Comedy Product is being broadcast on Channel 4 on Monday, 8 January at 2310 GMT.