LONDON Gordon Brown said on Tuesday the government needs to send a message that cannabis is "unacceptable," increasing speculation he will decide to tighten drug laws.
Brown has received a report from The Advisory Council on the Misuse of Drugs (ACMD) on cannabis and will decide soon whether to upgrade it to Class B from a Class C, although a decision is not expected this week.
Newspapers have predicted that Brown will reclassify the drug even though the council has reportedly advised the government to keep cannabis in Class C.
"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," Brown said.
"I have always been very strongly of the view that cannabis is unacceptable and we have got to send a message," he added.
Brown said he was particularly worried about the growing use of skunk cannabis, which he described as "more lethal".
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 Brown launched a review by the advisory council, which comprises doctors, police, judges and counsellors, soon after he became prime minister.
Brown's spokesman said on Tuesday the government had a requirement to take into account the council's views "and the views of others".
Going against the council's advice would be controversial, given it plays a large role in setting drug policy.
The Conservatives have accused Brown of dithering over the issue.