Gordon Brown's government will announce on Wednesday whether it plans to reclassify cannabis, in a move that is set to draw criticism whatever the outcome.

The decision on whether to upgrade cannabis to Class B from Class C follows a government-commissioned review by an independent body, which will also publish its findings on Wednesday.

Speculation is rife that Brown will reclassify cannabis as a Class B substance, going against the advice of his advisory council that is expected to endorse the status quo.

Government officials declined to comment ahead of the announcement but Brown said last month he wanted to send a strong message that use of the drug was "unacceptable".

Cannabis was downgraded to Class C - which includes substances such as anabolic steroids - in 2004.

That means possession of the drug is treated largely as a non-arrestable offence.

But proponents of a tougher drugs policy say its Class C status ignores the potential mental health effects of cannabis, particularly stronger variations like "skunk".

Mental health criminal lawyer Grahame Stowe, a partner at law firm Grahame Stowe Bateson, said reclassification of cannabis was long overdue.

"Those of us who work in the criminal and mental health spheres of the legal industry are acutely aware of the danger cannabis poses and the long-term damage it causes," the lawyer, who has 35 years' experience, said in a statement.

"Reclassification is the only way to address this problem and make concrete progress on tackling cannabis use."

The Advisory Council on the Misuse of Drugs (ACMD) was asked by Brown shortly after he took office last June to review the drug's classification and it reported to ministers last week.

The council will make its findings public about the same time as Home Secretary Jacqui Smith unveils the government's decision to parliament, expected at 12:30 p.m.

Going against the council's advice would be controversial given it plays a major role in drugs policy but Brown would also come under fire from those who say the current policy is too soft if he decides to keep the drug in Class C.

Last month, Brown hinted he favoured reclassification.

"I don't think that the previous studies took into account that so much of the cannabis on the streets is now of a lethal quality and we really have got to send out a message to young people - this is not acceptable," he said.

He added he was particularly worried about the growing use of skunk cannabis, which he described as "more lethal".