Some very valid points here from everyone.
However, the Licensing Act 2003 superceded all the old laws about 'minors' in the pub.
It was true about 14 years to be in a pub; 16 for "beer, cider and perry" (note, not wine originally) "with a meal"; etc. etc.
Even then, though, these were minimum ages by law - so if a Licensee decided that no-one under 18 was allowed to be in his pub, then he has absolute right to stipulate this, despite the (then) Licensing Law saying a 14 year old may be on Licensed Premises.
As an ex-Licensee, I have seen many people who think that it is a right under Licensing Law, when it merely sets the minimum, legally permissible age.
Similarly, "Permitted Hours" - this defines the hours you are allowed to open, NOT the hours you MUST open.
And finally - "Public House" - ie 'pub' - means the Licensee is granted permission to allow members of the public into The Premises to purchase and consume alcoholic liqour. It does NOT mean the public have a right of entry!
(If I had a penny for every time I heard"IT's a public 'ouse innit? Then I'm the public an' I can come in", swiftly followed, {upon being asked to leave} by "You don't know 'oo I am !!" - then I'd have about �2.84p)