Senior MPs have called for action in the 'war on drugs' as part of a reform of the UK's system on illegal substances.
The Home Affairs Committee told David Cameron that the current approach is not working, with some suggesting that legalisation could be the answer.
In an effort to consider all solutions, experts are even looking at the approach taken in Portugal, where the emphasis is on drug treatment, rather than law enforcement.
MPs want to find out what we can learn from Portugal, where users of small amounts of drugs escape criminal punishment if they attend a 'Dissuasion Commission'.
They argue that harsh custodial punishments are part of the problem, as some users only become addicted to legal substances once they're in prison.
The Home Affairs report also comes days after parts of the U.S. altered their drugs legislation.
Washington state has become the first state in the U.S. to legalise marijuana, and other states like Colorado could follow suit.
The Home Affairs Committee visited Portugal, Colombia and the U.S. as part of their analysis.
They advised David Cameron to set up a royal commission to consider all alternatives to Britain's current drug laws, including decriminalisation and legalisation.
Critics say this commission isn't necessary as drug use in Britain is at an all-time low.
But as Mr Cameron today rejected calls for a royal commission, stating that the current policy in Britain is working, we take a look at how the problems are approached abroad, as well as the issue of 'legal highs'.
WILL THE PORTUGESE SYSTEM WORK?
Under controversial measures first introduced in 2001, Portugese authorities establish whether drug users are hardcore addicts or casual drug takers.
The 'Dissuasion Commission' then stops criminal proceedings if a persistent user agrees to treatment.
They will impose punishments if users go back to drugs however, and drug trafficking is still prohibited.
The punishments include restrictions on meeting certain people, and bans on certain types of employment.
If the drug user stays clear of illegal substances, they have no criminal record.
Upon their return, the Home Affairs Committee urged health ministers to visit Portugal to see the effects of replacing criminal punishment for drug use with treatment.
They say the Portguese system 'clearly reduced public concern about drug use', and was backed by the police and all political parties.
The Portugese argue that their system works because fining drug users is counter-productive.
Explaining the findings, Keith Vaz, the committee's chair, told BBC Radio 4's Today programme: "They're giving people a choice there.
"Portugal is quite different from the United Kingdom so there are lots of reasons why that might not work here.
"But they given people a choice, go into treatment or go into the criminal justice system, and the Portuguese, strong Catholic country, actually seem to be supporting this."
Mr Vaz insisted, however, the committee weren't suggesting directly replicating the Portugese approach, merely 'monitoring the situation... to see if we can learn any lessons'.
Despite the apparent benefits of the European approach, drug campaigners still oppose a move towards rethinking the UK's drugs policy.
Mary Brett, of the charity Cannabis Skunk Sense, told the Daily Mail: "A royal commission would cost the earth, and we do not need it to tell us what we already know: legalisation would open the floodgates and drug use would increase."
WHAT ABOUT LEGAL HIGHS?
The Home Affairs Committee also analysed the effect of 'legal highs' which have come into widespread use since 2010.
'Psychoactive' substances like Mephedrone and 'Mexxy' are not classified under the Misuse of Drugs Act 1974, as they are specially produced to bypass these regulations.
Alarmingly, the report claims that 'legal highs' are so widespread that last year UK police discovered a new substance almost once a week.
Currently, legal highs can be subject to a 'Temporary Class Drug Order', where they are prohibited for 12 months while officials decide how to classify the drug.
During this period, importation, exportation, production and supply is prohibited, but possession is not.
MPs say this system needs to be overhauled. Temporary orders are seen as a 'stop gap' solution, which cannot keep up with the speed at which new legal highs are produced.
The report says that legal highs present the 'most significant challenge to existing legislation and the Government's Drug Strategy'.
Although the Portugese approach of drug treatment is being considered for some illegal substances, MPs say it would not work for legal highs.
The speed with which new highs are produced, combined with the effect of social networking and retail outlets in promoting their supply, means current laws simply can't keep up.
Instead, the report states that the Government should issue guidance to trading standards bodies to tackle the sale of these 'untested substances'.
They reason that restaurants which give diners food poisoning, garages which leave cars faulty and shops which sell defective goods can all be prosecuted for negligence.
Under the same principle, retailers who sell 'psychoactive' substances, even under the guise of 'plant food' or 'not fit for human consumption' should also face criminal action.