German brothels offered customers to sleep with as many prostitutes as they want for a single fee

The "flat rate sex" promotions, which are based on all-you-can-eat restaurants, have been introduced by brothel owners in a bid to revive trade that has fallen around 30% in the economic downturn.

Other imaginative offers include rebates for pensioners and people on benefits, 10% discounts for men who arrive by bicycle or public transport, and free shoe polishing for customers who stay overnight.

But it's the flat rate deals which are priced as low as €70 (£60) that have attracted particular controversy in a country where prostitution is legal and generally well tolerated.

The promotion is popular which brothel owners who have to pay their sex workers a fixed daily wage whether they have any clients or not.

But conservative politicians have expressed disgust at the innovation and have ordered a wave of police raids on sex clubs in an effort to bring it to an end.

“This is an outrageous violation of human dignity,” Heribert Rech, the Baden-Württemberg interior minister, told THE TIMES MAGAZINE.

“So-called flat-rate sex is an immoral development which cannot be tolerated in the society.”

Because the promotion is not forbidden by law, officers have focused their raids on immigration and hygiene offences at brothels where it has been introduced.