Calls for a full Whitehall probe into chief whip Andrew Mitchell's angry rant at Downing Street police have been rejected.
Cabinet Secretary Sir Jeremy Heywood said he agreed with the Prime Minister that there would not be "any purpose" in an investigation after Mr Mitchell said sorry for the incident.
Our Deputy Political Editor Chris Ship reports.
The news came with Mr Mitchell still struggling to put an end to last Wednesday's incident, when he is said to have launched a foul-mouthed tirade at police officers who stopped him riding his bicycle out of the main Downing Street gates.
The MP repeated his regret when he went in front of cameras for the first time this morning. However, he refused to answer questions about whether he had branded the police "plebs" - as their leaked written records of the conversation suggest.
In the letter, Sir Jeremy said that the head of security at Number 10 and the Prime Minister's principal private secretary Chris Martin had talked to the police sergeant involved.