Drugs charities today criticised Government plans to withdraw welfare benefits from addicts who refuse treatment.
They said there was no evidence it would work and the idea could breach medical principles.
The Home Office is considering the prospect of some form of "financial benefit sanction" for claimants who fail to address their drug or alcohol dependency.
It would mark the revival of a scheme planned by the previous Labour government aimed at helping to get drug users back into work if implemented, but social security advisers have warned that such a move could drive addicts back into a life of crime.
Martin Barnes, chief executive of charity DrugScope, said: "The benefit system can and indeed does have a very important role in terms of advice and support to encourage people both to access treatment and employment.
"But we seriously question both the fairness and the effectiveness of actually using the stick of compulsion - benefit sanctions - to link a requirement to undergo medical treatment with a condition of receipt of benefit."
He said there was "absolutely no evidence" that would work for a "vulnerable and often marginalised group" and added that under principles enshrined in the NHS Constitution, "medical intervention should be therapeutic, consensual, confidential".
"I just don't see that's compatible with using the benefits system to require people to undergo a complex form of drug treatment intervention," he said.
The idea was raised in a Home Office consultation paper on the Government's drug strategy for England, Wales and Scotland.
It asks whether the Government should "be making more of the potential to use the benefit system to offer claimants a choice between some form of financial benefit sanction, if they do not take action to address their drug or alcohol dependency, or additional support to take such steps".
This support could include "tailoring the requirements placed upon them as a condition of benefit receipt to assist their recovery (for example, temporarily removing the need to seek employment whilst undergoing treatment)", the Home Office document said.
It comes amid Government plans for a wider shake-up of the welfare system to help save billions of pounds.
The Labour government planned a series of pilot schemes this year to help drug users kick their habits and return to work.
They included applying sanctions to addicts who failed to attend treatment awareness programmes, and increased powers for the criminal justice system to help identify problem drug users not in treatment.
But the Social Security Advisory Committee - a statutory body - warned the pilot could cause "significant harm".
Consequences could involve the "disengagement of problem drug users from the welfare to work system with ... negative economic and social impacts", the statutory body said.
The consultation proposals published today also outlined Government plans to quickly impose year-long bans to help take new legal highs off the market while a comprehensive review of their potential harm is carried out.
It comes after Ivory Wave was blamed for the death of chef Michael Bishton, 24, whose body was found in the sea in Whitecliff Bay, near Bembridge, Isle of Wight, on Saturday.
Earlier this week, a leading doctor said the Government should consider decriminalising drugs because the blanket ban has failed to cut crime or improve health.
Professor Sir Ian Gilmore, former president of the Royal College of Physicians, said he agreed that drug laws should be "reconsidered with a view to decriminalising illicit drugs use".
He called for the UK to take a fresh look at its laws and added there was a strong case for putting a regulatory framework around illicit drugs, rather than the current blanket ban.Reuse content