Pressure mounted on cabinet minister Andrew Mitchell on Friday after the Police Federation said it was "hard to fathom" how he could remain in office after being accused of hurling expletives at officers guarding Downing Street.
The chief whip has apologised for being disrespectful to police officers after they refused to let him cycle his bike through the gates on his way to No. 10.
According to The Sun the former Army officer told them: "Best you learn your f***ing place. You don't run this f***ing government".
Mitchell, who served as shadow police minister while in opposition, is also accused of calling the officers "morons" and, most damagingly, telling them they were “f***ing plebs".
The chief whip, who is in charge of internal Conservative Party discipline, said he had apologised for the way he spoke but denied using the strong language reported by The Sun.
However his apology was not enough for the organisation that represents rank-and-file police officers, which already has strained relations with the coalition over cuts to police budgets.
The Police Federation of England and Wales, which represents rank-and-file officers, said the behaviour was indicative of the way it was treated by the government.
Paul McKeever, the federation's chairman, said it was "hard to fathom how someone who holds the police in such contempt could be allowed to hold a public office".
"Mr Mitchell's half-hearted apology for the comments made whilst leaving Downing Street will do little to build bridges with the police, who feel they have once again been treated with a lack of respect and civility by members of this government," he said.
"The lack of regard that some within government appear to hold police officers in is especially disappointing during this tragic week for the service and does nothing for the rock bottom morale of officers in this country."
A spokeswoman for No. 10 said David Cameron was aware of the outburst, "is glad that Mitchell has apologised" and added that police "should always be treated with respect"
The timing of the row is particularly sensitive following the deaths of police officers Fiona Bone and Nicola Hughes who were shot dead in Manchester this week.
Labour's shadow home secretary Yvette Cooper said the allegations were "appalling" if true and police officers and public servants should be treated better by ministers.
"And the idea that a Cabinet Minister could behave like this towards police officers doing their job is an utter disgrace," she said.
Responding to the reports, shadow defence secretary Jim Murphy tweeted "Some of these Tories are foul-mouthed spoilt little brats".
And former Conservative Party chairman Lord Tebbit denounced Mr Mitchell's comments as "extraordinarily stupid" and urged Mr Cameron to have a "heart-to-heart talk" with his new chief whip.
As well as offending the police, Mitchell's use of the word "pleb" is especially toxic for the government as it often has to fight accusations that it is led by "posh boys" who are out of touch with the average voter.