Iain Duncan Smith and Oliver Letwin will today sit in on a therapy session for addicts after unveiling their latest thinking on drugs.

The Conservative leader and shadow home secretary are visiting a Promis counselling centre in west London.

They will launch a consultation paper fleshing out more detail on youth crime policies unveiled at the Tories' conference last month.

Letwin has branded the governments liberalisation of cannabis policing a "muddled and dangerous policy" and backs an expansion of drug rehabilitation facilities.

"I propose that we should actively identify those young people who are on heroin and cocaine, and that we should face them with a choice: treatment (including all the psychological and other help required to beat the menace) or off to court," he said in Bournemouth.

"To make a reality of this policy, we will need greatly to expand the amount of treatment available in this country for heroin and cocaine addiction. We will need to multiply treatment tenfold - to the same level that we see in countries like Sweden."

Duncan Smith and Letwin will later join a one hour counselling session which will include sufferers with a range of addictions.

"All addicts of any kind (alcoholics, drug addicts, sufferers from eating disorders, gamblers, sex addicts - the lot) are treated alongside each other," says the Promis website.

"The human problems of addicts are identical whatever the specific addiction, and it is the management of these human problems that form the core of treatment at Promis."

The group which backs Conservative policy on drugs treatment rejects harm minimisation, methadone and needle exchange as "complete anathema".

"The life available on prescribed drugs is a life devoid of genuine feeling. Is that what we would tolerate for our own loved ones?," the Promis website asks.

More controversially Promis considers the basis of drug addiction to be genetic.

"Addicts commonly want to blame their childhood experiences and current social circumstances for their addiction. Promis believes. the basic addictive nature is probably genetically inherited."

Treatment, the group argues, cannot bring a cure.

"The primary form of treatment is to provide an understanding of the nature of addictive disease and what needs to be done to keep it in remission on a continuing daily basis for the rest of the addict's life," says the website.

Promis offer "an online evaluation of your addictive tendencies".

The questionnaire reveals that leadership hungry Westminster politicians may have more deep-rooted problems.

"I tend to look for or take on positions of power or influence so that I rise to a position of emotional or practical power over others as rapidly as possible."

"When I feel that my position of power or influence is under threat I tend to neglect other aspects of my life," are statements indicating an addiction problem reveals the web survey .