British Deputy Prime Minister Nick Clegg has vented his ire on coalition partners as the Conservatives rejected a Home Office study backing decriminalization of drugs.
"The war on drugs is not working," Clegg said in his weekly phone-in programme on LBC radio.
"They need to explain to the British people why they think it is OK to carry on with an approach which is leading to two thousand people losing their lives in this so-called war on drugs every year."
The Liberal Democrat spoke as British MPs debated drugs policy after the Home Office published a report by a panel of experts favouring decriminalisation of mood-altering substances.
The New Psychoactive Substances Review concluded that treating drug possession as a health problem rather than a criminal matter has no impact on levels of substance misuse.
The House of Commons was discussing a motion proposed by Green MP Caroline Lucas in the wake of a petition which gathered more than 100,000 signatures.
"The bottom line is that this is not about being pro-drugs. It's about saving lives and the only credible way to do that properly is to know whether our policies are up to the job," she told MPs in the debate.
"This isn't about legalising, it's not about a free for all, it's actually about bringing regulation and control back into the market which is currently in the hands of gangs and others who don't care what are in these substances," Lucas said.
However, a Home Office spokesperson said: "This government has absolutely no intention of decriminalising drugs."
David Cameron's official spokesman made clear that the new study had not persuaded the Prime Minister to change his view on drug policy.
"The Prime Minister thinks the current approach the government is taking is the right one and isn't going to change," the spokesman told a regular Westminster media briefing.
"The government said in 2010 that there would be a comparative analysis and that is what has been done. At the heart of it is that countries take the approach that is most effective in each of their territories."
Clegg said on LBC: "I think the Conservatives are just sticking their head in the sand. I think they're wrong".
"There have been countless other reports which have also suggested we need to take a smarter approach, where we are smart and compassionate towards the addicts who need treatment, but much tougher towards the Mister Bigs and the pushers, who should be behind bars," Clegg told listeners.
"At the moment we are letting the pushers get away with it and we are putting the addicts behind bars. It is completely the wrong way round."
The Home Office panel warned that an "analogue" anti-drugs legislation, that bans certain drugs, might spark the development of new ones.
"This, in turn, may lead to more harmful substances including illicit drugs or new groups of substances being developed," they said in their analysis.
They also warned that new drugs controlled by law "may still be in demand and could increase involvement of organised crime groups and displace sales to the internet."
The panellists proposed instead a general prohibition of psychoactive substances, with exemptions for substances the government wishes to permit, such as alcohol, tobacco, caffeine, energy drinks.