Labour has called for government chief whip Andrew Mitchell to come to the Commons to explain exactly what he said to a Downing Street police officer.
Shadow leader of the House Angela Eagle made the demand during exchanges on future Commons business on 18 October 2012.
Mr Mitchell is reported to have sworn at an officer when police directed him away from the main gate to a smaller pedestrian gate and said "learn your place" and "you don't run this government".
He is also alleged to have used the word "plebs" but the chief whip denies this.
In the Commons, Ms Eagle noted the chief whip's "inexplicable" absence from the green benches despite the "long-standing" convention that they should be "seen not heard" in the chamber.
"He would be well advised to observe that convention outside this House too," she quipped, referring to Mr Mitchell's outburst.
She claimed the chief whip "keeps changing his story" and demanded he come to the despatch box to clarify what he said.
"But perhaps he's too busy repairing relations with the Conservative backbenchers to bother to attend business questions," she remarked.
Leader of the House Andrew Lansley defended the chief whip, saying he was doing his job well and was "in his place but he also has duties elsewhere in this House".
Mr Mitchell had apologised for his outburst and this had been accepted both by the officer involved and the Metropolitan Police, he said.
"I will take no lectures today or indeed next Wednesday when the opposition day debate on the police takes place about the support this government gives to police," Mr Lansley added.
Mr Mitchell could later be seen in his place on the frontbench.