Former cabinet minister Andrew Mitchell sues The Sun newspaper over the “plebgate” row after it ran a story in which it claims the chief whip swore at police and called them “plebs”.
Lawyers for Mr Mitchell, who resigned from the cabinet after claims he argued with police on leaving Downing Street, have issued a libel writ against the paper, which first ran the story.
It follows confirmation by the Crown Prosecution Service (CPS) that it has a received a file from Scotland Yard in relation to the investigation.
The Sun says it stood by its story “and will defend this claim vigorously”.
The original story said Mr Mitchell, then chief whip, swore at police officers and called them “plebs” after they stopped him exiting Downing Street by the main gates to the street.
So far, three officers have been arrested as part of the investigation sparked by the row about the incident on 19 September.
Those arrested include a 52-year-old from the Diplomatic Protection Group who was held on 15 December on suspicion of misconduct in public office and bailed until April.
Two 46-year-olds from the same command were held on 31 January and 1 February for allegedly passing information to the media and were bailed until May.
All three remain suspended. A 23-year-old man who does not work for the police was also arrested and bailed until May.
A CPS spokesman said: “We have received initial papers but we have not received a full file of evidence and we now await the conclusion of the police investigation before considering charges.”