Peter Tatchell is famous for annoying the hell out of people.

Whether confronting the Archbishop of Canterbury, Robert Mugabe or Mike Tyson, the gay and human rights campaigner takes a literal approach to the dictum "speak truth to power". For many years Tatchell was regarded with deep suspicion by the mainstream. His controversial stunts, which included outing bishops and staging a mock crucifixion of a gay man outside a cathedral, did not exactly enamour him to the Establishment.

Then came his attempted citizens' arrests of Zimbabwe's president Robert Mugabe, first in London in 1999 and then again in Brussels in 2001, after which he was badly beaten by the tyrant's henchmen.

Suddenly Tatchell found himself lauded as a brave fighter for justice. Even the Daily Mail carried an article describing him as an heroic example to us all.

Last Thursday the Pavilion Theatre played host to the hero as part of the Brighton Festival's books and debate programme. There were no books to plug and no real debate. Instead the audience was treated to an hour and a half of glorious ranting.

Tatchell dived straight into politics, castigating the international community for failing to stop genocide in the Darfur region of Sudan. Tatchell said: "Four-hundred thousand Darfurians have already died and two million have been forced out of their homes. We need a no-fly zone and peacekeepers to disarm the militias. Sit up, do something, shout."

Then he was off calling for a popular uprising to tackle Britain's unfair voting system. He said: "When letter writing and lobbying don't work then sometimes breaking the law and being prepared to go to prison is what is needed to shake things up and challenge those in power."

Festival events often take the form of genial conversation after which the audience goes home comfortably sated, their consciences salved, until the next timetabled session of edification.

So it was a welcome wake-up to witness Tatchell's fury as he railed against the world's many injustices in a rallying call for action.

After 30 years of rebellion this action man shows no sign of tiring.