Conceived by Saatchi & Saatchi, the posters have been the subject of 240 complaints to the advertising watchdog. An ASA spokesman said it represented "an exceptionally high level of complaint on the basis of taste and decency" and that the authority had written to the advertiser for comment.
One poster shows a close-up of a healthy young man wearing underpants with the slogan "Girls, can we interest you in a package holiday?", while another reads "Beaver Espana". One slogan considered but not adopted by the agency was "Now even Everton fans can score away from home".
Most complaints accuse the campaign of being either "obscene", "irresponsible in encouraging promiscuity" or just plain "offensive".
Club 18-30's campaign, launched in the Midlands, north-east England and Northern Ireland, has some way to go before topping the 800 formal objections prompted by the Benetton poster featuring a new-born baby, but it has already edged ahead of the 167 complaints for another Benetton advertisement showing a dead soldier's bloody uniform.
The holiday advertisements have caused particular offence in Northern Ireland, where the company has doubled the number of holidays sold this summer. The Rev Martin Smyth, Ulster Unionist MP for South Belfast, was reported as saying that on moral and health grounds, the advertising industry was "sinking to new depths".
Chris Clark, group account director at Saatchi & Saatchi, said: "We never set out to offend, we just intended to be honest about the product. We hope most people will look at the posters and smile."
During the Seventies and Eighties, Club 18-30, an offshoot of the International Leisure Group (ILG), became synonymous with drinking, dancing and bed-hopping. But in the late 1980s, the tour operator made an effort to tone down its salacious image in line with the new climate of Aids awareness.
As well as promoting "romantic" deals for couples, it limited numbers allowed in single-sex bookings and emphasised the fun and fitness aspects of its holidays. Out in the resorts, however, the emphasis remained less politically correct.
After the collapse of ILG in 1991, the tour operator was reborn as The Club, but many observers felt that the "sex, sea and sangria" holidays so popular in the Seventies and early Eighties were out of favour with today's young.
But the resurrection of the Club 18-30 name - which according to new research is embedded in the minds of 96 per cent of British youth - and the new, blatantly sexual campaign from Saatchi and Saatchi, shows that after a period of apparent self-denial inwhich Club 18-30 claimed "mineral water and self-restraint'' was its motto, the holiday company has robustly returned to the sex-in-the- sun holidays which caused a furore a decade ago.Reuse content