LONDON - Gordon Brown faces a grilling in parliament on Wednesday over the funding row that has engulfed the Labour party, the latest in a series of setbacks to rock his government.
Despite condemning the donations as illegal and pledging to return them, Brown will face more calls to explain what he knew about the 600,000 pounds that property developer David Abrahams donated through intermediaries.
Conservative MPs say the affair is "getting murkier by the minute" and will attempt to pile on the pressure at Prime Minister's Questions at midday.
Electoral laws require those making donations on behalf of others to give details of the source of the money.
Abrahams said he didn't realise that using middlemen to donate to Labour was illegal and that he had merely wanted to avoid publicity.
"Until Friday, I didn't know it was illegal," Abrahams told the BBC. "If I had known at the time, I would most certainly not have donated in that way."
One of those named in the media as an intermediary, secretary and school lollipop lady Janet Dunn, said she was a lifelong Tory and knew nothing about the payments.
Abrahams also said he received a letter from Labour's chief fundraiser Jon Mendelsohn on Tuesday, thanking him for being "one of Labour's strongest supporters".
Labour's General Secretary Peter Watt resigned on Monday after the row erupted at the weekend. Deputy Labour leader Harriet Harman said she will return 5,000 pounds she received for her leadership campaign.
Labour said it had launched an inquiry on Wednesday.
The Tories likened the episode to the sleaze that blighted Tony Blair's later years in office, in which it was alleged that titles and peerages were awarded in return for donations.
Shadow Cabinet Minister Chris Grayling said: "The whole affair becomes murkier by the minute. Gordon Brown still has a lot of serious questions to answer."
Acting Liberal Democrat leader Vince Cable said: "This sleazy affair is far more serious than initially thought and could be a matter for a criminal investigation."
The fiasco is the latest challenge for Brown, who took over from Tony Blair in June and whose popularity has plummeted since his perceived dithering and lack of nerve in failing to call an early general election in the Autumn.
Since then, the Northern Rock collapse and the loss of two discs with the personal details of half the nation have eroded public confidence in his leadership, polls suggest.
