Calls for a government-backed inquiry into the decriminalisation of drugs will be debated by Liberal Democrats at their annual conference next month.
Some delegates want more emphasis put on the treatment rather than the prosecution of drug users.
The Lib Dems will debate a motion which would become party policy if it wins support at the Birmingham conference.
But they would still need the agreement of the Conservatives before an official government inquiry could be set up.
'Criminal records'
The motion will urge the government to set up an expert panel to consider the decriminalisation of personal drug use.
It insists that current drugs laws are "harmful" and "ineffective".
Some Lib Dems believe savings could be reinvested in education, treatment and rehabilitation programmes.
Drug users would no longer face a prison sentence or a fine but would be required to go for treatment or counselling. Penalties for drug dealing would remain the same as they are now.
The motion states that there is "increasing evidence that the UK's drugs policy is not only ineffective and not cost-effective but actually harmful, impacting particularly severely on the poor and marginalised".
It continues: "Individuals, especially young people, can be damaged both by the imposition of criminal records and by a drug habit, and... the priority for those addicted to all substances must be healthcare, education and rehabilitation, not punishment.
"One of the key barriers to developing better drugs policy has been the previous Labour government's persistent refusal to take on board scientific advice, and the absence of an overall evaluative framework of the UK's drugs strategy."
Greater scrutiny
It will not be the first time the Lib Dems have discussed changing the drugs laws at their annual conference, and in 2002 delegates voted for the legalisation of cannabis.
But BBC political correspondent Iain Watson says any call for an inquiry into drugs legislation is likely to attract far greater scrutiny now the Lib Dems are in government.
The inquiry would look at adopting the practice in Portugal of decriminalising the possession of drugs for personal use, and following the Swiss example of providing more clinics for heroin addicts.
The motion will be put forward by Ewan Hoyle, founder of Liberal Democrats for Drug Policy Reform, and supported by Lib Dem MEP Sir Graham Watson.
Party members can submit amendments to the motion by 5 September, ahead of the conference on 17-21 September.
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