The UK Air Navigation Order is a legal instrument which among many clauses says a passenger should not be allowed to board an airliner under the influence of drink, nor become drunk while on board. Easy to write, less easy to enforce while hundreds of passengers crowd the gate, many under the influence of tax free bottles opened illegaly in the departure area. This was the case on many holiday charter departure flights from the UK to European destinations. On one such midnight departure from Manchester to Palma Mallorca carrying 230 pax in my B757, crew of 2 pilots and 6 stewardesses it was evident from the start that at least 30 rowdy male pax were about to cause problems for my crew. Under the ANO I refused them boarding and left with a much relieved cabin crew and the remaining happy 200 pax, many with children. This problem was solved permanently by the holiday company informing all bookings that anyone refused boarding while drunk and disorderly would lose their holiday without recompense, and if refused on the return would have to fund their own flight with another airline. This tactic worked.