More than half of Americans want marijuana to be legalised

More than half of Americans support legalising marijuana use, a record level, amid growing support for reform that could build pressure to eventually change laws on the drug, a Gallup poll shows.

The poll shows that support is highest among liberals and adults under 30, with more than 60 per cent of respondents in those categories favouring legalisation. Support is lowest among Americans over 65, at just 31 per cent.

"Support for legalising marijuana has been increasing over the past several years, rising to 50 per cent today, the highest on record," a summary of the poll says. Another 46 per cent say marijuana should remain illegal.

"If this trend on legalising marijuana continues, pressure may build to bring the nation's laws into compliance with the people's wishes," the summary adds. Gallup says support for legalisation has crept up from just 12 per cent in 1969 to 30 per cent in 2000 and 40 per cent in 2009.

Last year, a Gallup survey found 70 per cent of Americans favoured making it legal for doctors to prescribe marijuana to relieve pain and suffering.

California in 1996 became the first state to decriminalise medical marijuana, and a number of other US states have followed suit with their own statutes. Cannabis remains classified as an illegal narcotic under federal law.

A separate national survey released last month showed that marijuana was increasingly becoming the drug of choice among young adults in the United States, with nearly 7 per cent of Americans aged 12 and older having used marijuana in 2010.