IT may not be on the scale of Peter Hain’s £100,000 expenses scandal, but it seems that the prime minister has himself slipped up when it comes to filing his election returns.

Gordon Brown was forced to go to court to explain why he had not declared a £200 bill in his expenses for the 2005 general election. Brown was compelled formally to petition the court in Edinburgh or face a maximum £5,000 fine and a six-month prison term for making a false election declaration.

Court documents show Brown admitted that the agent for his Kirkcaldy and Cowdenbeath seat had made an “erroneous” declaration, forgetting that rates had to be paid on an office he had hired from Fife council.

The disclosure may prove uncomfortable for Brown, who as chancellor earned the tag Prudence for his attention to the nation’s finances. He has said in relation to Labour’s funding scandals that he has not “micro-man-aged” the party’s accounts.

The documents admit that Brown approved an inaccurate statement about how much was spent on his local campaign. He had approved the expenses which he had “believed . . . to be full and accurate and in proper form”.

Brown had relied on Alex Rowley, his constituency agent, to make the declaration. “The aforementioned errors arose by reason of inadvertence on the part of [Rowley],” the documents say. “As a result of the erroneous return, the declaration was in error as a consequence.”

His offence was not to include a payment for rates on the hire of an office from Fife council, unaware that a “nondomestic rate charge” was payable. The bill for the rates was sent by Fife council at the end of May, but the person to whom it was addressed was on holiday.

The admission by Brown, who did not attend court, meant that no further action was taken.

Lord Oakeshott, the Liberal Democrat Treasury spokesman, said the mistake was embarrassing: “No wonder Brown couldn’t screw himself up to sack Hain when he’d had to ask a court in Edinburgh not to fine him for incompetence in declaring his own election expenses.”

A spokesman for Brown said that the failure to declare the expenses in full was simply “an oversight”.

Labour is facing two police investigations into donations, including an inquiry into the deputy leadership expenses submitted by Hain. The works and pensions secretary was forced to resign last week after breaking electoral rules when his staff failed to disclose thousands of pounds of donations to his deputy leadership election campaign.

Harriet Harman, deputy party leader, is under investigation by the Electoral Commission over her deputy leadership election expenses. The watchdog is looking at a donation made to her by David Abrahams, the property developer, her decision to take out a mortgage on her home to fund her campaign and other donations made to her campaign to fill a funding gap.

Sources close to the minister have expressed confidence that she has broken no rules.

Des Browne, the defence secretary, said he was confident that no more ministers’ expenses would be referred to the police. He told BBC Scotland’s Politics Show that he did not expect any more resignations on the issue.

Times Recommends

• Donor organ allowed child’s own heart to heal
• Michael Jackson: Not the final chapter
• Brüno toned down for 15 rating