Fight promoter Frank Warren says he stands to lose £600,000 of his own money if Mike Tyson is not allowed into Britain to fight Julius Francis.

And Francis could become bankrupt if the fight - scheduled to be held in Manchester on 29 January - is cancelled.

Tyson and his American entourage have confirmed they will definitely arrive in London on Sunday, despite warnings from the government that former world heavyweight champion may be barred from entry because of his criminal convictions.

The scene is set for a showdown at Heathrow airport between Tyson and immigration officers.

Warren has accused some Labour MPs of playing politics with the boxer.

"The problem we have got now is that some poor guy has got to make a decision with all this pressure," Warren said.

"At one stage the Prime Minister was saying he shouldn't be let in, so the Prime Minister is saying don't you make that decision.

"I got a letter on Wednesday from (the Prime Minister's press secretary) Alastair Campbell.

"He sent me a letter saying I was wrong on TV to say that this Government was wrong to interfere.

"He said he didn't say Mike Tyson had little chance of coming to Britain, he said it was a matter for the immigration department."