An alcohol ban, announced by new London Mayor Boris Johnson, comes into effect on the Tube, London buses, Docklands Light Railway and tram services across the capital.

From Sunday, drinking from - and carrying - open containers of alcohol will be banned. Party-goers clutching copious quantities of alcohol met at Liverpool Street Station's west-bound Circle Line platform.

Londoner Matt Wynn, 43, a banker, said: "I've come along with a bottle of champagne because I want to show that you can drink responsibly on the Tube and not cause trouble. It's going to be a bit of a stop-start evening, though, because there are no toilets on the Tube."

Tara Harrison, 26, from Australia, said: "When I heard about it, I had to come along. I don't think (the ban) is a good idea, because it's not going to work. People get on the Tube when they're already drunk, they don't get on the Tube to drink."

Her friend, Steve Nosworthy, 27, also from Australia, said: "I've brought along this big crate of Carling and I'm going to go round and round all night - well, until 12 o'clock, when I'll probably get kicked off."

One man who thought he had found a loophole in the new drinking rule was Alias Cummins, a managing director from London, who had brought along a Portini. He said: "It's a portable martini, it comes with a lid, so at 12 o'clock I can seal my drink and they can't touch me."

One passenger hoping to wow fellow party-goers was Steve Urwin, 20, a professional street magician. He said: "I've just brought along a four-pack of Budweiser because I'm going to performing tricks to entertain the passengers on the Tube."

The Rail Maritime and Transport Union General Secretary, Bob Crow, said the ban on alcohol on Tube trains was "half-baked" and could put staff at greater danger of assault.

But Mr Johnson said: "I'm determined to improve the safety and security of public transport in London and create a better environment for the millions of Londoners who rely on it. The ban has the full support of the Metropolitan Police and British Transport Police."