Why Kaye, of course, for calling himself a "cunt for starring in Bates' latest TV ads for Woolworths. According to Kaye and his agent, his comments in a national newspaper - "I've just done an advert for Woollies. What a cunt. I'll have to hide from the telly for six months" - were misunderstood and the jibe against himself was meant to be taken as a joke.
Woolworths immediately issued a statement, saying how surprised it was to read Kaye's colourful comments. "Paul Kaye's agent assures us he was misunderstood, and that such a misunderstanding will never happen again, the retailer said in guarded tones.
Kaye isn't the first celebrity to embarrass a client and he won't be the last. Linking a well-known face with a product makes for product-shifting advertising, with an estimated one in five campaigns in the UK now using the device.
While IPA Effectiveness Awards, happy clients and long-running campaigns are the positive side of the story, there are several classic examples of what happens when things go wrong. There's Ian Botham, who appeared in an ad for a low-alcohol beer and then confessed it tasted like "gnat's piss", Helena Bonham-Carter, the face of Yardley, who confided to a national newspaper that she never wore make-up. Just this year, footballer Roy Keane, the star turn in 7-Up's summer campaign for the Republic of Ireland, caused a cock-up when his row with the manager Mick McCarthy saw him kicked out of the team just days before the World Cup kicked off.
The legal and contractual issues involved in making sure it all doesn't end in tears are immense. If they don't have legal experts in-house, agencies will work with media law firms to ensure both client and celebrity know what is expected as part of the deal. It is unlikely that Kaye's contract allowed him the freedom to express his views of Woolworths in such a frank way.
Bates will not comment on Kaye's contract, but Giles Crown, a senior communications lawyer at Lewis Silkin, says there's a checklist which every agency should tick off before embarking on any campaign featuring a celebrity.
First is deciding who to approach. At the very least, agencies should check press cuttings and assess a celebrity's suitability for backing a brand based on whatever they find. "Making these kind of preparations means agencies can tailor contracts for a celebrity. Also, for insurance purposes it's crucial to be aware of any past problems, or it could mean you're not covered in the event of a hitch, Crown adds.
It's also important to establish how the celebrity will be expected to appear. For example, using Carol Vorderman to endorse Benecol in a testimonial-style ad is different from, and falls under a separate set of regulations to, Prunella Scales portraying the character of Dottie for Tesco.
"Agencies will then approach the talent's agent, pitching the deal and declaring information such as how long the contract will run for, the media which will be used, the exposure and the number of days a year they'd be needed for shoots, Crown adds.
At this stage, he says it's important to iron out any issues the celebrity might have with the type of exposure. "Every eventuality has to be thought of, from whether the person will appear on packaging, point-of-sale material, in cinema ads, for store visits or other events. It can cost more to amend a contract later and advertisers can themselves be in breach of contract if they use an image for an unagreed medium, he warns.
But just as important are the insertion of clauses which give the client some assurance that their association with a celebrity isn't going to turn into a millstone. "Conduct clauses are essential, obviously depending on who an agency is asking to front a campaign, and most will prohibit celebrities from making derogatory comments about the brand or company for a period of 12 months after the ads have finished running," Crown says. It's normal for that period to prohibit celebrities from talking about the ads at all.
There's also the question of how far the endorsement goes. If the celebrity claims to swear by the product being advertised, there must be back-up to prove it - for example, Anna Kournikova wearing Adidas clothing and shoes while playing tennis. Similarly, there may also be clauses to ensure that the star must be seen to advocate the client's business even if they are only acting a part within the ad. Scales is contractually obliged to shop at Tesco - when she was seen in a branch of Sainsbury's it was embarrassing for all parties. Jamie Oliver, whose contract with Sainsbury's was deemed so entrenched by the BBC that it decided not to continue to make The Naked Chef, also embarrassed the supermarket when his wife was spotted shopping at Waitrose.
The client can sometimes be the source of embarrassment, though. Such as when Alan Davies, the star of Euro RSCG Wnek Gosper's campaign for Abbey National, applied to the building society for a credit card and was refused.
So what now that Kaye has made his gaffe? Crown claims it's rare for a client to exert muscle in defending itself in this kind of situation.
"The PR implications are massive - just as the celebrity signing itself allows clients and advertisers to benefit from positive coverage, they will have to cope from the adverse coverage which inevitably follows from this kind of incident, he explains. However, often the expense and trouble involved in pursuing the breach of contract through the legal system far outweighs the benefit.
Kate Fulton, Y&R's legal counsel in the UK, was responsible for drawing up the contract for John Thompson who stars in Rainey Kelly Campbell Roalfe/Y&R's Lloyds TSB campaign. While she won't discuss Thompson's recent exposure in the press for a drink/drive offence, Fulton is convinced that the best way to solve contractual issues - whether caused by bad behaviour or by other infringements - is by mutual, amicable agreement.
"Getting aggressive is not the answer, she says, recalling one instance with a celebrity. "We had exclusivity on this person, meaning they were contractually obliged not to appear in ads for other products in the same sector, when we saw an ad on the TV, starring them, for a rival brand, she says. Negotiations resulted in extra ads being made, free of charge - a considerable compensation.
Fulton also points out that celebrities are often chosen for their potential to provoke a reaction, and suggests that this was why Bates and Woolworths chose Kaye. "He's got the ads talked about, she says.
Who knows, we might even start to copy the US, where a recent report suggested that advertisers were actively encouraging their celebrity campaign stars to behave badly. "No morals clauses are becoming common, as clients with youth brands look to cash in on the coverage which follows a scandal. As one Bates executive claims, "Any PR is good PR."