The cross-party Football Group has demanded the deal be referred to the Office of Fair Trading, fearing a conflict of interest if a major sports broadcaster were to own the club.

Buy-out goal: Rupert Murdoch

And the MPs say they want a chance to debate the takeover bid in Parliament before any decision on the proposal is made.

The News Corporation empire, chaired by Mr Murdoch, is the biggest shareholder in satellite broadcaster BSkyB, which holds exclusive rights to show FA Carling Premiership matches.

"Not good for football"

Joe Ashton, Labour chairman of the Football Group, said the government would have to act, because MPs from all parties as well as the public were angry at Mr Murdoch's action.

Demanding a debate: Joe Ashton

He said: "This is about a few people wanting to make themselves very rich.

"Murdoch wants to sit on both sides of the table. That has to be against Office of Fair Trading principles.

"Last week there were talks about having a new Super League. Sky weren't at the table and Murdoch is worried that if it goes ahead and he's not there, he could lose out, so to make sure he's got a seat at the table he's trying to buy Manchester United.

"That may be good for Sky TV but it's not good for football or for trade."

Government promise

Trade and Industry Secretary Peter Mandelson has given an assurance that any Murdoch takeover of Manchester United would be investigated carefully by the OFT.

He said: "If a bid goes ahead, it will be notified to the Director General of Fair Trading and he will look at it very completely and extremely searchingly."

Mr Mandelson added: "The Director General will examine the competition aspects and will then report to me and I will take whatever action I need to take."

Ministers worried

Foreign Office Minister and Manchester Central MP Tony Lloyd told the BBC there may be concern about an unhealthy degree of control from the point of view of supporters.

"Unhealthy degree of control": Tony Lloyd

"It may be good business for BSkyB but we would need to know it was also good business for the football-watching public," he said.

It raised questions both about the future of the club and about broadcasting, he said.

Sports Minister Tony Banks said an OFT investigation was possible because of the "very profound" consequences of any deal.

According to the Financial Times, leisure group Enic is considering making a rival bid.

Satellite TV now accounts for a substantial proportion of the earnings of top football teams.