Gordon Brown has been rebuked by the Westminster sleaze watchdog for subletting taxpayer-funded office space to Labour Party colleagues.
The Prime Minister "inadvertently" broke rules by allowing premises in his Kirkcaldy and Cowdenbeath constituency to be used.
No punishment will be sought because Mr Brown has apologised and neither he nor the party benefited financially, the Standards and Privileges Committee said.
In its report, the committee added: "We conclude that Mr Brown should not have sub-let part of his accommodation paid for from Parliamentary allowances.
"However, neither Mr Brown nor the Labour Party derived any financial benefit from this arrangement and there was no intention to deceive.
"We accept that Mr Brown's breach of the rules of the House was inadvertent and that he took steps to rectify it as soon as it was drawn to his attention.
"Mr Brown has apologised and, in our view, no further action is necessary."
Conservative frontbencher Greg Hands, who lodged the complaint against Mr Brown, said he accepted the premier's apology.
He said: "It does not appear that the Prime Minister has personally profited from the breach, and he did quickly rectify the situation when it was brought to his attention by my complaint and by the media."
The rebuke - though light - will be embarrassing for the premier, who has gone to great lengths to distance himself from sleaze rows in the past.
