Embattled Chief Whip Andrew Mitchell should give a full account of his row with police at the gates of Downing Street, Deputy Prime Minister Nick Clegg has said.
The Liberal Democrat leader's intervention came after it was reported that police logbooks showed Mr Mitchell called officers "plebs" and swore repeatedly during the altercation.
Mr Mitchell has denied using the word pleb, but Mr Clegg said a full explanation was necessary.
He said: "I don't know what happened, I don't think anybody knows precisely what happened and there are rival versions being circulated in the press. I think, therefore, it's really important that Andrew Mitchell explains fully and in detail his version of events."
Unpublished records made by members of Scotland Yard's specialist protection team, which have been seen by The Sun newspaper, contradict the Tory enforcer's statement about the tirade he launched when he was stopped from cycling out of the main gates near No 10.
Mr Clegg had previously called for a line to be drawn under the issue, but now said it was vital to hear Mr Mitchell's account.
He said: "I don't know what happened, it's very difficult to adjudicate, but I think it's important that, when one set of events is being described in the newspapers, we hear Andrew Mitchell's side of the story because this is a serious issue. He did something wrong, very wrong, he has apologised and now there are these rival versions circulating."
Pressed on whether an inquiry would be needed to get to the truth, Mr Clegg said: "I rather hope it doesn't come to that, that we have to spend money on an inquiry into a version of events about what one individual has said to another. I hope people will just honourably tell the truth."
The police reports, made for senior officers, detail how the Tory was warned that he would be arrested under the Public Order Act if he swore at the team again, according to The Sun. The record is backed up by verbatim notes of the exchange made in the pocket books of two other officers, it said.
"The officers involved would have been happy to let the matter lie once Mitchell apologised," a source told the newspaper. "But their integrity is now being called into question by Mitchell's denials and that is totally unacceptable. Perhaps with the full verbatim report in the public domain, people can make up their own minds."