Richard Brunstrom said all drugs should be legalised
The Police Federation, which represents 128,000 officers up to the rank of inspector, voted overwhelmingly that police should "enforce and seek to strengthen" current laws.
North Wales police chief Richard Brunstrom told 700 delegates at the federation's annual conference in Bournemouth that all drugs including heroin and cocaine should be decriminalised.
But only 30 officers supported a motion backing decriminalisation.
Mr Brunstrom, who has called for a royal commission on the legalisation of all drugs, believes Britain's fight against them is "almost an unqualified disaster".
He told delegates the drugs trade was worth £275bn a year - more than the global petroleum industry.
And the amount spent on illegal drugs in the UK equalled the police's annual budget of £8bn.
Mr Brunstrom added that heroin was largely safe.
But tobacco and alcohol caused many more times the number of deaths than all illicit drugs put together.
"It is very hard to die from heroin - most people die from the impurities in the drug or from overdoses.
"The sum total of all the effort you and I put into this is to turn heroin into a commodity so expensive addicts have to commit crime after crime to feed their habits."
But, to thunderous applause from the audience, Derbyshire drugs squad sergeant Steve Holmes replied: "What an insult.
"Most heroin users were criminals before they ever used drugs.
"Let's get stuck in and make arrests and make a difference."
Two weeks ago the Association of Chief Police Officers said heroin and cocaine users who commit offences like burglary, theft and street crime while on the drugs should be sent for treatment instead of being prosecuted.
And in March the Metropolitan Police said it would continue a scheme in Lambeth whereby people caught in possession of cannabis are let off with a warning.