To clarify the many issues raised by respondents in this question, there can no longer be any Byelaws made to prevent the anti social aspects of drinking on the streets.
The Criminal Justice and Police Act 2001 (CJPA) gave local authorities the power to designate public areas through the introduction of a Drinking in Public Places Order where it is an offence to drink alcohol after being required by a police officer not to do so. The police have the power to require individuals to surrender the alcohol and any opened or sealed containers, and if they fail to comply with the request they can be arrested. The powers � which replaced the old drinking byelaws - were introduced to help the police deal with the problems of anti-social drinking in the public space. DPPOs make it easier for local authorities to designate places where restrictions on public drinking will apply and can be used in areas that have experienced alcohol-related disorder or nuisance.
However, such areas do not operate in an area where the supply is covered by a Club Premises Certificate. So, if the outside area was covered by the Clubs Certificate, you are fine and the Police can take no action. If they were not, you can be asked to pour the drink away or be arrested. If no request to dispose of the alcohol is made, there can be no come back or arrest.
To complete the legalities, you are able to buy alcohol in a sealed contained in a club, if you are a member, to take out of the premises and consume it somewhere else. If you are a guest, you are not.