Across all age ranges, around three million people continue to take drugs, half of whom are aged 16-34.

If drugs were decriminalised, however, the proportion of Britons who have never previously tried drugs but who would consider doing so in the future would increase fourfold to 16%, offering some proof to hardliners that drug laws act as a deterrent.

The effect would be most pronounced among young people. Among 16- to 24-year-olds, 30% of those who have never taken drugs say they would consider doing so if substances were decriminalised.

The recession appears to have a had an impact on drug consumption. In the 2008 poll, conducted towards the beginning of the global economic slump, 35% of users were more likely to use drugs in a pub/club/bar environment. This has now fallen to 16%, possibly an indication of more straitened circumstances. Users spend an average of £74.36 on drugs each month, compared with the £54.58 an average drinker spends on alcohol a month or the £76.73 a smoker spends on tobacco.

Concerns that legal highs would create an explosion in drug use have yet to appear, with only one in 10 Britons saying they had tried them. Among those aged 25-34 the proportion to have tried legal highs almost doubles to 19%.