LONDON (AP) -- Marijuana should be legalized because it is a largely safe drug that can alleviate some symptoms of multiple sclerosis, AIDS and cancer, the sponsors of Britain's first public conference on the issue declared Thursday.

Body Shop founder Anita Roddick, one of the sponsors, told an often-rancorous audience of 500 that Britain's current policy regulating marijuana is ``random, foolish and harmful'' and ``turns the sick into criminals.''

``It is time to change the law,'' she said.

The conference, also sponsored by Virgin boss Richard Branson, was brought together by The Independent on Sunday newspaper, which has mounted a campaign to enable Britons to buy and grow marijuana legally.

Some at the conference expressed concern that marijuana use was a ``gateway'' to harder drugs, but they were in the minority.

Nigel Evans, a lawmaker from the main opposition Conservative Party, was heckled when he said marijuana could cause madness. ``Keeping it controlled is the only way we can keep the number of young users down,'' he insisted.

British property owners face jail terms of up to 14 years for allowing someone to smoke cannabis on their premises. Government figures show that there are at least 1.5 million marijuana users, with more than 656,000 arrests made for cannabis-related offenses between 1967 and 1995.

Prime Minister Tony Blair's Labor government, which came to power on May 1, says it has no plans to decriminalize marijuana, despite a recent British Medical Association report that marijuana has therapeutic value in treating the symptoms of some diseases.

The medical journal Lancet concluded in 1995 that ``the smoking of cannabis, even long-term, is not harmful to health.''

Labor lawmaker Austin Mitchell, who earlier this month led a delegation to the Department of Health asking for marijuana to be made available on prescription, said he had been told there was not enough research on the subject.

``Pure balderdash,'' Mitchell thundered Thursday, waving a copy of the BMA report from the floor. ``Thousands and thousands of multiple sclerosis sufferers are being forced into the back streets.''

Balancing on a pair of crutches, MS sufferer Barry Clarke complained that he has to be a criminal to obtain marijuana to relieve muscle spasms.

``Why can't I grow it in the privacy of my own home and smoke it?'' Clarke said. ``That's all I ask.''

Rosie Boycott, editor of The Independent on Sunday, urged other countries to follow the Netherlands, which allows its citizens to use marijuana for therapeutic and recreational purposes.

Other speakers went further, urging full legalization.

Sociology professor Lynn Zimmer, co-author of a report on marijuana research published by U.S. philanthropist George Soros' Lindesmith Center, said the drug ``has some potential for harm, but not too much.''

Soros, a billionaire currency trader, was among the financial backers of a California law, approved by voters in 1996, that allows marijuana to be grown and used for medical purposes if recommended by a physician.

Decriminalizing marijuana, Zimmer said, would enable police officers to focus on other crimes -- in effect ``expanding current police forces by 5 or 10 percent.''

``Last year in the United States, the police arrested 500,000 people for possessing cannabis,'' she said. ``By my calculation, these arrests cost American taxpayers about $500 million.''