Activist and comedian Mark Thomas is on the police’s Domestic Extremists Register, as are about 9,000 other people.

In Cuckooed, Thomas told his personal story of betrayal by fellow anti-arms’ trade activist, ‘Martin,’ who was spying for BAE systems.

For years ‘Martin’ had been a stalwart campaigner, best-friend, godfather and confidante to campaign members.

Intelligently disclosed with wit, passion, sadness and anger, the tale clearly rang true to others in a similar predicament, who described their experiences in film clips, including women duped by undercover policeman they’d had relationships with.

The sold-out show began with 30 minutes of stand-up, in which Thomas humorously described some of his decades’ worth of daring protest antics.

When posting over UKIP posters, he revealed: “the irony of hi-vis jackets is that you can get away with anything - people just think it’s the council.”

Exposing the disturbing extent of underhand surveillance and the damage it inflicts, Thomas said: “Deception is a heady drug and you have to control how it’s used.”

The monologue also revealed Thomas’s complexity - between the F-word in abundance, he would depict scenes with poetic descriptions such as “the sun was shining down the river from the east like a golden dart.”