Boxer Mike Tyson can stay in the UK for his fight later this month after a women's group lost its legal bid to declare his entry illegal.

The pressure group Justice for Women was refused an application for a judicial review of Home Secretary Jack Straw's decison to allow the former world heavyweight champion to fly into the UK on Sunday, despite a rape conviction which would normally have seen him barred.

Following a 90 minute hearing, Mr Justice Sullivan said the degree of discretion allowed to Mr Straw in decisions of this nature made it "unarguable" that he had exceeded his powers in granting exemption to immigration rules.

The judge said, even if it had been arguable, it was unlikely he would have granted a judicial review, due to the practicalities of stopping the fight at such a late stage.

He said: "Because of the effect in financial terms on innocent third parties, along with many thousands of people who have bought tickets, it really is inconceivable that the fight should be halted."

Mr Justice Sullivan said he wanted to make it clear the court did not condone rape, but could not accept Mr Straw had acted above his powers.

Julie Bindel, who heads up Justice for Women, said she was "very disappointed" and the group was considering taking the matter further.

She said: "What the judge said about the interests of third parties is somewhat different from our view."

Tyson was chauffeured out of his Grosvenor House Hotel base, on Park Lane, central London, on Monday afternoon, accompanied by fight promoter Frank Warren.

Followed by a posse of paparazzi, Tyson visited a luxury sports car showroom and several designer clothes stores in the West End as well as a mosque.

He is expected to spend the next 10 days at the hotel, ahead of his 29 January fight against British champ Julius Francis at Manchester Arena.

The US boxer is also planning to hold several press conferences and at least one charity visit to a hospital as part of a "charm offensive".

Although campaigners and politicians have objected to Tyson's presence in the country, his fans have displayed a very different reaction.

On arrival at Heathrow on Sunday, the boxer was faced with a scrum of fans and media so intense that one reporter got knocked over and had to be taken to hospital.

Crowds of fans have also been waiting to catch a glimpse of Tyson at the hotel, although they have been far outnumbered by the press.

At one point on Monday, Tyson's entourage allowed 12-year-old Lisle Britton, from Newmarket, Suffolk, to come into the hotel and spar with the American.

Afterwards the schoolboy said: "He was very nice. He was practising in the ring and I got in there and messed about a bit."