At each of his last 16 gigs, in front of a total of 10,000 people, he gave out the private addresses of Ian Lang, president of the board of trade, and Michael Heseltine, the deputy prime minister, and urged his fans to send them unwanted mailings.
Although neither minister was available to confirm it, Thomas claims they have both received more than 3,000 items including free condoms, information about penis extensions and how to learn Afrikaans in 10 days.
"It's an imaginative piece of revenge," Thomas said. "I thought it was a perfect form and content to raise a protest. They are trying to privatise the Post Office through the back door by using the strikes as an excuse. Using junk mail against them is like fighting fire with fire."
Thomas is known for the political pranks he has played on his Channel 4 show, The Mark Thomas Comedy Product.
He says he has not heard from the ministers involved, but is confident they were irritated.
Thomas says other members of Parliament he has annoyed in his 12-year career have included Tony Blair, Tony Banks, William Waldegrave, Malcolm Rifkind, Edwina Currie and Sir Nicholas Soames.
A Post Office spokesman said: "The Royal Mail takes the view it is an irresponsible thing to do to channel mail in this way to two individuals."