The Home Secretary has been urged by a health charity to look at the mental health risks of cannabis, rather than "fiddle with its legal status".
The charity wants to focus on cannabis' risks
In a letter to Charles Clarke, Rethink called on him to devote resources to reducing the risks of the drug.
Cannabis was downgraded from a Class B to a Class C drug in 2004, making most cases of possession non-arrestable.
The Home Office said Mr Clarke was due to respond soon to an Advisory Council on the Misuse of Drugs review.
The charity wants him to support new research into the relationship between severe mental illness and cannabis, and the most effective ways of reducing use.
It is calling for government policy to tackle cannabis-dealing around mental health facilities, similar to that for dealing around schools.
Rethink chief executive Cliff Prior said it did not want a knee-jerk reaction of stiffened penalties from the Home Office.
That, he said, "will only lead to further confusion amongst high-risk groups and could lead to thousands of people being dragged through the courts rather than supported through health and social care".
"We want to see Mr Clarke reacting imaginatively by handing responsibility for a huge public information campaign to the Department of Health whilst facing down siren calls to further criminalise users.
A Home Office spokesman said: "The Advisory Council on the Misuse of Drugs has recently reported to the home secretary.
"They have been considering evidence on possible links between cannabis and mental health problems.
"The Home Secretary is considering their report and will respond in due course."