Sharon Osbourne doesn't think marijuana should be legalised.

The 62-year-old star has revealed she thinks it's a mistake that four US states have chosen to decriminalise the drug and hopes that Britain doesn't choose to follow suit.

She said: ''Anything that alters your mental state I don't think should be allowed.''

The TV personality - whose husband Ozzy Osbourne has struggled with drug and alcohol abuse in the past - claimed making cannabis legal will result in more accidents.

She told America's CBS TV: ''The next thing I am waiting for is when someone is working heavy machinery, when they are driving a car. It is all going to end in tears.''

However, Sharon predicted that the relaxation of laws won't last long and that the changes will end up being reversed.

She added: ''In years to come there will be new laws for those who are smoking and using marijuana.

''This will end not the way everybody thinks it will.''

The former 'X Factor' judge's comments come after a number of celebrities called for the drug to be legalised across the Untied States.

'Ted 2' actress Amanda Seyfried said recently: ''I think it's a wonderful thing, and lots of people use it responsibly, and it should be legal.

''I don't understand how people can die all the time from alcohol poisoning, yet pot is so stigmatised.''

Susan Sarandon has also spoken about the subject at length, claiming she'd like to ''see everybody be able to smoke pot''.