Gordon Brown was struggling to escape the grip of expenses scandals again today as another cabinet minister was forced to issue an humiliating apology and pay back money.
After Alistair Darling seemingly came close to conceding that his time as chancellor was running out yesterday, Transport Secretary Geoff Hoon admitted he had "accidentally" overclaimed £384 in similar circumstances.
The scale of the damage being inflicted on the party, two days before crucial local and euro elections, was reinforced in a poll that suggested its support had plummeted 10 points to just 18% since the row erupted.
Deputy Labour leader Harriet Harman warned a meeting of the parliamentary party last night that its position had been "challenging" before, and was now "even more difficult".
Meanwhile, another backbencher, Jim Devine, was referred to the party's "star chamber" over allegations that he submitted receipts from a firm that may not have existed.
Mr Darling became engulfed in fresh controversy over his use of Commons allowances when the Daily Telegraph reported that he had broken the rules by claiming for two properties simultaneously.
The chancellor initially branded the accusation "completely untrue", but then announced that he would pay back around £350 in service charges on his London flat. The bill was apparently paid in advance shortly before he moved into grace-and-favour accommodation in Downing Street in 2007.
"I'm sorry about that, I unreservedly apologise," he said in a round of broadcast interviews. "I do not want, as I said, to make a gain I am not entitled to. That is why the money has been repaid."
Mr Darling also gave the impression of being resigned to leaving Number 11, in a Government reshuffle expected as early as Friday. Schools Secretary Ed Balls has been mooted as a potential successor.
"I have enjoyed the last couple of years, Gordon has worked very closely with me," Mr Darling said. "It is up to the Prime Minister. He has got to decide the team that he wants to be in the next government."
Pressure was building on Mr Darling all day yesterday, as the Prime Minister accepted his neighbour's mistake had been "inadvertent" but repeatedly refused to guarantee he would still be chancellor in a week's time.
In his own frenetic round of broadcast interviews, Mr Brown also raised eyebrows by using the past tense to stress Mr Darling "had been a good chancellor".
David Cameron accused the premier of hanging his minister "out to dry", and said he should either "back him or sack him".
The Lib Dems went further by insisting the chancellor must go because he had lost the "moral authority" to manage the nation's finances.
Mr Hoon said sorry last night for an almost identical transgression, having apparently used Commons expenses to pay the TV licence, gas maintenance bill and home insurance at his Derbyshire property for a year in advance in 2006.
However, when he was demoted from Leader of the House to Europe minister that July and lost the right to live in a grace-and-favour apartment in Admiralty House, he bought a new flat in London and "flipped" his second home designation so he could claim expenses on it.
That meant he was effectively claiming on two properties at the same time.
In a statement, Mr Hoon admitted: "After I left Admiralty House there was an entirely inadvertent overlap in bill payments.
"This was entirely accidental. As soon as this was brought to my attention I repaid £384 for the additional months of TV licence, British Gas homecare agreement and home insurance, covering the months remaining in the year after I moved.
"I repaid the money as soon as this was drawn to my attention and although this was an inadvertent administrative error, I unreservedly apologise for the mistake."
In a further blow for Labour last night, the Daily Telegraph reported that backbencher Alan Meale had claimed more than £13,000 for his garden over four years.