Comedian Mark Thomas is to join with National Union of Journalists members in an event to highlight the threat of a new UK law that could be used against press photographers taking pictures of the police.

The Counter Terrorism Act allows for the arrest and imprisonment of anyone whose pictures are “likely to be useful to a person committing or preparing an act of terrorism”.

The union is joining with campaigners to organise a mass picture taking session outside London’s police HQ on Monday 16 February, the day the act becomes law.

Mark will be joined outside New Scotland Yard by renowned documentary-maker Chris Atkins, NUJ vice-president Pete Murray and a bevy of photographers.

Photojournalist and NUJ member Marc Vallee said: “The plan is simple, turn up with your camera and exercise your democratic right to take a photograph in a public place.”

There have already been cases of photographers stopped from working by police quoting anti terror laws.

John Toner, the NUJ’s organiser who looks after freelance photographers, said: “Police officers are in news pictures at all sorts of events, football matches, carnivals, state processions, so the union wants to make it clear that taking their pictures is not the act of a criminal.”

“Our members are photographers, not terrorists.”

Roy Mincoff, NUJ Legal Officer, said: “Photographers do not want to endanger the health and safety of the police or the public, but it is important in a democracy that they can do their jobs properly without facing unnecessary legal restrictions.”

The photo taking will start at 11am outside New Scotland Yard on Broadway, London.