Plans to ban the drinking of alcohol on London's transport system have been unveiled by new mayor Boris Johnson, the BBC reported.
He joined London's transport commissioner Peter Hendy to set out a timeline for bringing in the measure.
The ban, starting on 1 June, on the Tube, buses, trams and Docklands Light Railway is one of his election pledges.
But the Rail Maritime and Transport Union said the policy appeared "not to have been thought through very well" and could make matters worse.
It is part of Mr Johnson's wider strategy to tackle anti-social behaviour. New posters were also unveiled advising passengers of the no-alcohol policy.