The Police Federation is supporting the officers in their application for judicial review of the probe by the Independent Police Complaints Commission (IPCC).
Federation representatives Inspector Ken MacKaill, Detective Sergeant Stuart Hinton and Sergeant Chris Jones were initially told they would face no action over accounts they gave of a meeting with Mr Mitchell the month after his row with officers in Downing Street. The initial decision is now being reconsidered.
Mr Mitchell became involved in a heated confrontation with officers in September 2012 after he was refused permission to cycle through the main gate at Downing Street. He later admitted swearing but denied he called officers "plebs".
He later met with Mr Hinton, Mr Jones and Mr MacKaill in his Sutton Coldfield constituency to clear the air, but a further row was sparked when the officers told journalists that he had refused to reveal what he said in Downing Street, something apparently contradicted by a recording of the meeting.
The Police Federation said papers seeking judicial review have been lodged at the High Court in London and a decision is due to be made. A spokeswoman said: "Following a request to consider the lawfulness of its decision the IPCC was asked to suspend its investigation and an invitation to the officers to attend for interview. This was declined.
"There was no option but to lodge an application for judicial review,."