The Prime Minister has ordered an investigation into the attendance of a convicted rapist at a Labour party fund-raiser.
Gordon Brown has also insisted no money should be accepted from Owen Oyston.
The disgraced tycoon was at Wembley Stadium on Thursday night at a party where guests paid £10,000 for a table.
Oyston was jailed at Liverpool Crown Court for six years in May 1996 for raping a 16-year-old would-be model. He was released after three-and-a-half years.
Labour MP Stephen Pound, who attended the fund raiser, described Oyston's attendance as "downright embarrassing".
He said: "He shouldn't have been there and somebody is going to have to explain why he was. I can only assume that someone didn't recognise him because (Oyston's conviction) was quite a few years ago."
The MP added that Mr Brown would have been "absolutely disgusted" by the revelation and had made clear that money should not be taken from him.
"Say what you like about Gordon Brown, but he has an absolutely flawless and spotless reputation in that area," Mr Pound said.
Martin Bell, the anti-sleaze campaigner and former independent MP, said Mr Brown had acted "pretty fast" but warned that "people's perceptions are important".
A spokesman for Mr Brown said: "Mr Brown did not meet Mr Oyston, nor was he aware of his presence in advance.
"Mr Brown has asked the general secretary of the Labour Party to investigate the circumstances, but he has already instructed him that any donation from Mr Oyston should not be accepted."
Former prime minister Tony Blair was at the event, along with figures from the world of sport such as Sir Alex Ferguson and Newcastle manager Sam Allardyce and other celebrities including Simply Red singer Mick Hucknall.
What a fucking hypocrite McStalin is considering that both he and Adolf Blair having been raping this country for over a decade.