Mark Thomas, Tricycle Theatre, London

An undiminished appetite for tackling the ills of the world

While critics turn their flamethrowers on aspects of Michael Moore's Fahrenheit 9/11, fellow conscience-pricker Mark Thomas, once unfairly described as "the poor man's Michael Moore", has embarked on another of his own crusades.

His third show in four years divides into a "How to" of direct action ("liberation has to be fun, you can't change things by committee meeting") and an assault on that icon of the free world, the Coca-Cola corporation.

Though once described by Chris Morris as "a guy who goes round and bullies receptionists", Thomas's campaigning track record is impressive, particularly with regard to curtailing British involvement in the Ilisu dam, a development that threatened to displace thousands of Kurds. His appetite for confronting the ills of the world as he sees them is undiminished, in fact it seems to grow with each scrape.

Nevertheless, his "war stories" or rather "peace pranks" do wear thin; middle-aged versions of knocking off the policeman's helmet can only be arresting for so long. Yes, there is humour in every protest, in every banner or every T-shirt be they "Lesbians Against Bush" or "Embarrassed Americans against the War" but often the subsequent civil disobedience is similarly cutesy, a chucklesome distraction neither pithy in humour nor striking at the heart of the issue. Because of the sheer enthusiasm of Thomas's delivery some of the characters along the way seem to blend into one another. However, he doesn't lack humanity in his approach to his subjects and the best moments of the first half come when he notes the idiosyncrasies of campaigners, be they members of the public or politicians like the Scottish Socialist Tommy Sheridan, who we are told has an answerphone message thus: "Hello this is Tommy Sheridan. I'm out right now fighting Tony Blair's Tory policies and I hope you are doing the same."

In the second hour of the show, with the wind beneath his caffeine-boosted wings Thomas sets about debunking Coca-Cola. The US economy's entanglement with the Nazi regime in Germany rears itself as a pet issue. Rather than try to smear from a distance of 50 years Thomas argues that this history lesson has been repeated a number of times by the soft drinks giant which has invested in areas where suspect regimes are in power.

There can be little doubt of the current public appetite for dissent. Our very own homegrown "Axis of Evil", Thomas, Robert Newman and Mark Steel, continue to attract new audiences bewildered by a Government they no longer trust. The trio put a fresh spin on old causes, achieving what Thomas describes as "riding the wave of dissent not making the mistaking of being the wave".