Ms Bass and her staff are briefing the Brits on how to beat the system at the festival, and get themselves and their product noticed. First though they have to get fed and watered, hence the five o'clock scramble.
"I'm advising the Brits out here how to blag their way into the nightly parties," said Ms Bass. "It's the only way for many of them to eat and drink, when you remember a gin and tonic here can cost pounds 8.
"They have to get those precious party tickets. The nightly screenings are always followed by a party, and it means running up and down the Croisette at 5pm and badgering the PR offices for tickets.
"And if you can't get tickets you have to blag your way in. It's easy if you're a girl because you flirt with the doorman. If you can't do that then always have the name of someone high up on a particular film and say you are related to them. But make sure that their spouse or partner is not standing directly behind you."
More than 100 Cannes virgins went to a private Cannes Survival teach- in in London for a guide to serious networking "take an index box as well as normal business cards". They were particularly instructed to rehearse their pitch nightly in their hotel rooms "over and over again", and (in a style reminiscent of the Hollywood satirical film The Player) to be able to deliver it in three sentences.
"The whole of the world's film industry is squeezed into one street for 10 days," Harriet Bass told the nervous Cannes virgins. "You will be subjected to glamour and seediness."
The seediness, she said in Cannes yesterday, was the huge number of liggers and "triers on" desperate to be noticed. You see people come down full of hope and optimism and end up drunk in back street bars, after finding that no one wanted to buy or see their movies."
Enjoying much greater success but rapidly running short of money is Tom Waller, 22, one of the youngest film makers in Cannes.
He has produced and directed Monk Dawson, a film about a Catholic priest's affair with a parishioner, which stars a model-turned-actress, Paula Hamilton.
Yesterday Waller was on the Croisette, the Cannes sea front, giving postcards advertising his film's screenings to likely buyers, reviewers, movers and shakers.
He was also juggling his finances so that he could escort Miss Hamilton in the style to which she is accustomed, when she arrives for the round of interviews he has fixed up for her.
"I'm really here on a wing and a prayer," he said. "But I'm fixing things up so that when Paula does arrive she will at least feel like she's a minor celebrity.
"The problem is the expense. I'm going to have to end up paying for every coffee and every drink she wants to buy. And buying a drink here is extortionate. I'm sure they've put prices up because it's the 50th festival. I'll be drinking coke and I've just remembered Paula's off spirits, so that will help. But I've had to borrow money off my room mate, and credit cards are proving vital."
Andrew Curtis, an entertainment lawyer and a co chairman of the New Producers' Alliance, says it is not just film makers selling their wares in Cannes.
"Lawyers, particularly from the big London firms, go down and are very aggressive, approaching stars and trying to get new clients."
Cannes is a market where producers, lawyers and corporate executives buy, sell, network and wheeler-deal round the clock, with mealtime providing no respite.
Indeed, a few years back, two lines scribbled on the back of a restaurant napkin between a lawyer and his business client became the contract for Nightmare on Elm Street.