But that does not and cannot apply to a person over the age of 18 who stands in front of you, who is not excessively under the influence of alcohol, purchasing alcohol within the constraints of the law hotel21.
As with the sale of cigarettes it is the responsibility of the person actually selling the product to be satisfied that the member of the public purchasing the said product meets the legal criteria on the sales of such items. As a retail member of staff that is your responsibility, and as a senior manager within that same company (which I was and a holder of a liquor licence to cover my responsibilities over multiple convenience stores selling alcohol) I was responsible for the actions of all my staff (3,500!), but it was the member of staff and my company that would be prosecuted for any breach, which indeed a member of staff or so were in selling both cigarettes and alcohol to minors.
As a retailer though you are not held legally responsible for how that adult customer has acted or actioned with the product subsequent to purchase providing the original legal criteria on the selling of it has been complied with.

This must be the limit of all retailers concerns, including Tesco who are no different from the rest and are equal in the eyes of the law. 
Lizzie is absolutely spot on. And I am absolutely astounded, and disappointed in equal measure that certain members of the forum think, Tesco should have the powers to decide what a person over the age of 18 does with their legally bought alcohol after purchase.
Tesco are a retailer, nothing more.They are not God, and should have no powers to decide what happens after purchase. Indeed it is insulting, to even ask somebody over the age of 18 what they intend to do with their alcohol.
Lizzie has already mentioned people buying 18 rated DVDs being questioned about their intentions. Now they are doing it with alcohol.
I understand that £1 in every £6 is spent in Tesco. This worries me.
I shall be shopping elsewhere in future. Keep up the good work Lizzie

Thanks Optimist! This is a specialist professional subject for me, so I (usually

) know something about this subject even attending High Court, supported by a leading barrister, to present my company's legal case in acquiring liquor licences for our stores on appeal. We won!!

However, along with a fellow university student, I am constantly incensed by Tesco's attitude and actions in this country, with them actually being a political threat to the freedoms of the general public by establishing themselves as some state within a state due to their significant ecomonical and social power, often dictating what product is available to the public, how much it costs, what suppliers should survive or not, and of course how it is sold and to whom!!
There are also many small traders whose businesses are being blighted by Tesco's greed in acquiring land for future possible store development, but waiting until the aforementioned businesses are weakened before taking action. In addition they are using local political muscle (legally that' s all I can say) to pursuade councils to give them planning permission for more stores; a new roundabout here, new 'public' buildings there, etc.
Bit by bit, little by little, they are destroying the competition in the retail trade which is, in the long term at least, very unhealthy for us all and the many small, medium, and large suppliers who are squeezed almost to the point of not making a profit on what they sell to Tesco's by their ruthless buying power.
Competition is healthy, but monopolies are not, especially when they intefere in our democracy along with the moral rights and freedoms of British citizens.