It's not strictly legal (the inclusive ticket, or raffle ticket or donation systwm)- but many people do it, and I've never heard of it causing a problem.
The other possibility is to get someone connected with the school who is already a licensee to agree to apply for a temporary license to sell drink at the function - it's a form of extension. Stress the charitable fundraising angle in the application.
(I'm a licensee, btw, this my hazy memory of the stuff I had to read up on.)
It is illegal to sell raffle tickets or ask for donation for alcohol at any event.
You can apply to the licensing body for an occassional licence. This allows you up to 12 dates a year in which someone on the committee becomes the license and costs £10 for all 12 dates. You can change the dates but need to give 14 days notice. The licensee will be required to attend the court to be granted the licence.
Im the licensee for our PTA after the school got into serious trouble for selling raffle tickets in exchange for alcohol!!! Doesnt help that we have three trading standards chappies and four police officers on our PTA!!!!
You don't need to attend the court hearing - just make sure the form is in in plenty of time as the committee only meet about monthly to OK them. They will send you a list of dates if you ask. You then get a stamped sheet of paper back. Handy hint - if your event is from say 2 - 5 for a fete, ask for 1.30 to 5.30 just to cover yourselves. Also remember it's illegal to sell alcohol you've bought tax free abroad. Pain for us as we're 10 mins from Tunnel.
Everyone does the donation or raffle ticket thing, but bear in mind if you did get caught would you want all the adverse publicity for the school?