The award, for the most original and hilarious act at Edinburgh, is regarded as a virtual guarantee of instant fame and fortune. It has led to national success for Steve Coogan, Frank Skinner, Jenny Eclair, Lee Evans and, last year, Tommy Tiernan.
"After last year's award Tommy Tiernan's manager was immediately knee deep in faxes from people wanting to work with Tommy," says Nica Burns, the award's director.
The final five are, she says, a wide range of comedy acts, from stand- up to surreal and "scripted stuff". Stand-ups Terry Alderton and Ross Noble have made it, with surreal acts Arctic Boosh and League against Tedium (no relation to the League of Gentlemen who won in 1997, and secured a BBC television series).
Most controversially, however, Al Murray, the Pub Landlord, has secured a place as a finalist - despite the efforts of Ms Burns, who had argued that he was already too well-known to be considered. Her pronouncement dragged the Perrier Award into a dispute as fierce and bitter as those that regularly occur over the Booker Prize for literature.
Mr Murray, who acts the part of a xenophobic, little-Englander pub landlord, delighting audiences with jokes against the French and Scots, is represented by Avalon, one of the biggest agents in the comedy business. When Ms Burns disqualified Mr Murray, Avalon was incensed and challenged Ms Burns's view that its client should be excluded simply on the basis that he could already draw a good audience at "a mid-scale venue".
Two weeks ago Ms Burns decided to back down. Mr Murray, who is widely regarded as one of the strongest acts in Edinburgh, has now made the shortlist, but must wait until Saturday to learn whether his victory over Ms Burns and her edicts is to be complete.
Although Perrier is still the most highly regarded of the ever-increasing number of sponsored awards at Edinburgh, it has not been infallible in spotting future successes. Eddie Izzard and Jack Dee both failed to win it, as did Graham Norton, the gay Irish comedian who was shortlisted in 1997. With failure behind him, Norton has secured a contract with Channel 4, become one of the TV Times "50 coolest people on television", and has entered the heart of the establishment with his own show on BBC Radio 4.
But in the 1990s, only one act has gone from Perrier winner to utter obscurity. In 1994 aknockabout slapstick act from Australia called Lano and Woodley won the trophy, beating Harry Hill and Alan Davies, who have both subsequently secured television shows. "There are times when the Perrier loses its fizz," said a comedy agent. "They made the wrong decision - it happens."