Police officers at Downing Street threatened to arrest Chief Whip Andrew Mitchell after he launched a tirade against them for not opening a security gate, according to a log of the incident.
The report, written by police on the scene, conflicts with Mr Mitchell's account that he did not describe the officers as "plebs".
A 442-word account of the incident, published for the first time by The Daily Telegraph, records Mr Mitchell repeatedly refusing to comply with police requests and then swearing at officers. He was then warned he could be arrested under the Public Order Act unless he calmed down.
The report describes Mr Mitchell speaking to a female officer and "demanding exit through the main vehicle gate into Whitehall". He was told that it was "policy" for cyclists to use the pedestrian gate. "Mr Mitchell refused, stating he was the chief whip and he always used the main gates," the report goes on. "I explained to Mr Mitchell that the policy was to use the side pedestrian gates and that I was happy to open those for him, but that no officer present would be opening the main gates as this was the policy we were directed to follow.
"Mr Mitchell refused. Repeatedly reiterating he was the chief whip... After several refusals Mr Mitchell got off his bike and walked to the pedestrian gate with me after I again offered to open that for him.
"There were several members of public present as is the norm opposite the pedestrian gate and as we neared it, Mr Mitchell said, 'Best you learn your ******* place...you don't run this ******* government...You're ******* plebs.' The members of public looked visibly shocked and I was somewhat taken aback by the language used and the view expressed by a senior government official. I can not say if this statement was aimed at me individually, or the officers present or the police service as a whole."
The log states that the officer warned Mr Mitchell that he could be arrested for swearing. "I warned Mr Mitchell that he should not swear, and if he continued to do so I would have no option but to arrest him under the Public Order Act, saying 'Please don't swear at me Sir. If you continue to I will have no option but to arrest you under the public order act'," it states. "Mr Mitchell was then silent and left saying 'you haven't heard the last of this' as he cycled off."
The police officer who wrote the report stresses that officers were "extremely polite" to the Chief Whip.
Mr Mitchell appeared before television cameras to reiterate his regret over the incident. But he pointedly refused to answer questions about whether he had branded the police "plebs" - as their leaked written records of the exchange suggest.
Cabinet Secretary Sir Jeremy Heywood said he agreed with Prime Minister David Cameron that there would not be "any purpose" in an investigation after Mr Mitchell apologised for the incident.