Anti-terror laws are having a "chilling" effect on the rights of people to campaign and stage protests against government policies, comedian Mark Thomas said today.

He told the annual conference of the GMB union that even traditional campaigning on the doorstep could be regarded as harassment under some of the measures being introduced to fight terrorism.

He singled out the law banning demonstrations outsider Parliament without police permission as being particularly "ridiculous."

He told delegates at the Brighton conference: "I even had to get permission to wear a red nose in Parliament Square on Red Nose Day."

The comedian said a friend was questioned by a police officer for eating a cake opposite the Commons containing the word "peace" written in icing.

"The police are having an internal debate about this law because it's just not worth it," he claimed.

"The effect of these laws is to curtail our rights. They are having a chilling effect on campaigning and activism."