Andrew Mitchell
The Metropolitan Police Service seized a journalist's phone records to find information about Andrew Mitchell's 'Plebgate' incidentGetty

A group of journalists are to launch a legal appeal against the Metropolitan Police Service to force it to erase secret files it holds on their exploits.

The journalists, one of whom is comedian Mark Thomas, wants Scotland Yard to destroy a database at the National Domestic Extremism and Disorder Intelligence Unit that holds information on them.

The demand comes after the force has been under fire from journalists since it was revealed detectives seized the phone records of The Sun's political editor Tom Newton Dunn to identify his anonymous police source who tipped him off about the 'Plebgate' scandal that cost Conservative Andrew Mitchell his job as chief whip.

A Freedom of Information response from the the Met revealed that it holds 2,000 records relating to journalists and photographers.

But the force will not disclose how many individuals that information covers.

Thomas told the BBC: "The inclusion of journalists on the domestic extremist database seems to be a part of a disturbing police spying network, from the Stephen Lawrence family campaign to Hillsborough families, from undercover officers' relationships with women to the role of the police in the construction blacklist."

A spokesman for the Metropolitan Police said: "We can confirm that we have received a letter before action which we will respond to in due course."