Pop star George Michael fears he'll be forced to cancel his U.S. tour after his court case for driving under the influence of drugs. The singer pleaded guilty to driving while unfit due to drug use earlier this month (May07) after he was found slumped at the wheel of his car in London last year (07). And he fears he will now be refused a visa for his forthcoming trip to America. He told British talk show host Michael Parkinson at the weekend (19May07), "We've booked an American tour. It would be really sad. I don't think it's been announced yet but it would be really sad if I can't fulfil those dates. But I'm hoping that won't be the case, I'm just hoping that won't be the case."