Sir Bernard Hogan-Howe says that drug-testing would help cut the number of users - as the risk of losing your job would act as a deterrent.
"It seems to me we have got to plant in people’s minds something to affect the demand as well as supply. You can think of many occupations where if you were working with a colleague you would want to be sure in fact that they were drug free."
More top news
Two thousand women, and one very excited Barbara Windsor, put on their trainers today in a bid to raise money to fight cancer.
Two men have been jailed after a semi-automatic submachine gun was found hidden in a shoe box in a kitchen.
Negotiators are meeting today to try and stop a rail strike over an ongoing dispute over pay.