A report on cannabis prepared for next year's UN drug policy review will suggest that a "regulated market" would cause less harm than the current international prohibition. The report, which is likely to reopen the debate about cannabis laws, suggests that controls such as taxation, minimum age requirements and labelling could be explored.

The Global Cannabis Commission report, which will be launched today at a conference in the House of Lords, has reached conclusions which its authors suggest "challenge the received wisdom concerning cannabis". It was carried out for the Beckley foundation, a UN-accredited NGO, for the 2009 UN strategic drug policy review.

There are, according to the report, now more than 160 million users of the drug worldwide. "Although cannabis can have a negative impact on health, including mental health, in terms of relative harms it is considerably less harmful than alcohol or tobacco," according to the report. "Historically, there have only been two deaths worldwide attributed to cannabis, whereas alcohol and tobacco together are responsible for an estimated 150,000 deaths per annum in the UK alone."

The report, compiled by a group of scientists, academics and drug policy experts, suggests that much of the harm associated with cannabis use is "the result of prohibition itself, particularly the social harms arising from arrest and imprisonment." Policies that control cannabis, whether draconian or liberal, appear to have little impact on the prevalence of consumption, it concluded.

"In an alternative system of regulated availability, market controls such as taxation, minimum age requirements, labelling and potency limits are available to minimise the harms associated with cannabis use," said the report.

It claimed that only through a regulated market could young people be protected from the increasingly potent forms of cannabis, such as skunk. It is intended that the report will form a blueprint for nations seeking to develop a "more rational and effective approach to the control of cannabis".

The authors suggest there is evidence that "the current system of cannabis regulation is not working, and ... there needs to be a serious rethink if we are to minimise the harms caused by cannabis use."

Last night, the report was welcomed by drug law reform organisations. "The Beckley foundation are to be congratulated for the clarity of their call for cannabis supply to be brought within government control," said Danny Kushlick of Transform. "We look forward to the same analysis being applied to heroin and cocaine."

The report is being launched at a two-day conference, which will be attended by leading figures in the drugs policy world.

The conclusions are unlikely to be embraced by the government or the Conservative party, both of which are opposed to relaxing restrictions on cannabis use.