Criminal charges linked to the so-called Plebgate affair could be brought by the end of the month, Britain's most senior police officer said on Tuesday.
Metropolitan Police commissioner Sir Bernard Hogan-Howe said he hoped to hand a file to prosecutors in a matter of weeks, when the force closes its investigation into whether former chief whip Andrew Mitchell was the target of a conspiracy involving officers.
Appearing before the Home Affairs Select Committee, the Met chief revealed that a police officer arrested on suspicion of misconduct in a public office will answer bail on January 31, while a relative of the officer will answer bail on January 16.
Mitchell was forced to quit his Cabinet post amid a storm of protest - fuelled by the Police Federation - over claims he called officers "plebs" during an altercation in Downing Street.
Hitting out at the Federation for meddling in politics, Sir Bernard told the Committee it was not for the staff association to get involved with Mr Mitchell's resignation.
The Commissioner insisted he had an "open mind" to the inquiry in the face of criticism that he had hastily backed the police officers involved.
He admitted he made the comments before seeing the evidence that has since been made available - including CCTV footage of Mitchell exiting the gate to the Prime Minister's residence.
Committee chairman Keith Vaz recounted Sir Bernard's assertion shortly after the allegations emerged that the Met boss would "stand by" his officers "100%".
Vaz asked: "Are you still saying you stand by the events or do you now have an open mind?"
To which Sir Bernard replied: "I do have an open mind. If any comment that I have made left anyone thinking I couldn't have an open mind, I'm sorry."
He added: "I'm open-minded. I will pursue the evidence."
Mitchell has claimed he was the victim of a deliberate attempt to "toxify" the Tories and ruin his career after it was alleged an email from a civilian witness backing up the police account of events was in fact written by another officer.
Sir Bernard criticised public statements made by Police Federation representatives in the wake of the initial allegations against Mitchell.
Local Federation branches organised protests by members wearing "PC Pleb" T-shirts and demanded Mr Mitchell's sacking.
The Federation, which represents rank-and-file officers, has since said it planned an independent review into "issues" with its operations.
Sir Bernard told the Committee: "My concern would be from some of the public statements from the Federation's representatives is they got explicitly involved with asking for the resignation of a government member, and for me that is too much.
"That's a decision for the Government to make or the Prime Minister to make - and not for police officers to get involved in."
Committee member Michael Ellis MP asked: "Are you saying the conduct of the Police Federation was improper?"
To which Sir Bernard replied: "Those are your words, I'll stick with mine. It's not for the Police Federation or officers generally to call for the resignation of members of the Government."
Scotland Yard has decided to take statements from 800 police officers in the diplomatic protection group and 30 detectives are working on the investigation.
Sir Bernard added that part of the investigation was to identify the source of the leaked police log, which recounted the altercation with Mr Mitchell.
He told the Committee that if the allegations against the police officers involved were true, "it would be a very serious matter".
"I don't expect police officers to lie," he said.
Clarifying the terms of the inquiry, Sir Bernard said it set out to "investigate the circumstances surrounding the police officer's claims to witnessing the incident on Downing Street".
He said the inquiry set out to "establish if there's any evidence of a conspiracy between the police and any other persons".
"We expect we may be able to share a report with the CPS by the end of this month. A matter of weeks before we do as much as we can," he added.
The president of the Association of Chief Police Officers, Sir Hugh Orde, later told Channel 4 News the allegations of false police accounts of the "plebgate" affair should be seen "in perspective".
Sir Hugh told C4N: "I don't think it's evidence of routine endemic issues around corruption or integrity. We need to get it into perspective.
"It's an event that is almost unique in my police experience. The relationship between police and Government has to be one where healthy tension is the default position.
"We must get on with the job we are tasked with doing. We must then be held robustly to account, and this is what you saw today.
"We should take seriously any issues that damage the vital bond of trust between police and the citizen.
"Confidence is robustly high, confidence in policing has not been damaged because the public judge us on what we deliver."