The biggest sex show on earth

Armin Lobscheid is in a generous mood. "If you come back again we can put you up," he says. "You could stay here for a week!"

It's tempting, but I'm not sure what my fiancee would make of the offer. Herr Lobscheid is the manager of the biggest brothel in the world, the Pascha. Situated in the post-industrial suburbs of Cologne, every floor of this mammoth building boasts 20 rooms, each housing its own self-employed prostitute. The mega-brothel is open 24 hours a day, 365 days a year. Christmas Day is notoriously one of the busiest.

And why is Herr Lobscheid so happy? Because of the Fifa World Cup. This June, a million foreign football fans, primarily male, primarily young, are expected to invade Germany, and if previous World Cups and Olympics are anything to go by, a lot of them are going to be seeking commercial sex.

The fans won't be restricted to legalised brothels like the Pascha. Germany has one of the most liberal commercial sex industries anywhere, so the World Cup punter will be able to take his pick from several options. Most German cities boast clubs called FKKs (for Freikorperkultur or "free body culture"); once nudist clubs, they are now luxury saunas featuring paid-for sex.

Then there are the regular red-light zones packed with streetwalkers, such as Hamburg's Reeperbahn, and "dating bars" which double as bordellos, such as Berlin's Psst Bar.

In certain cases there are also special "tolerance zones" (once mooted for the UK), where the cheapest sex can be bought from the cheapest girls. Cologne has one of these zones at Geestmundestrasse, on the derelict outskirts of town. It's a truly weird place: the road dedicated to the prostitutes is protected from prying eyes by a vast green nylon curtain, yet the curtain has had holes ripped in it so voyeurs can peek at the sex-workers.

You might think these arrangements ample enough. Yet some German politicians are still worried that the supply of commercial sex won't meet World Cup demand. Cities such as Dortmund and Dusseldorf are consequently proposing to hand out free condoms to newly licensed prostitutes. Other towns are building "portable sex huts", where prostitutes can ply their trade.

Many of the girls are expected to be Eastern European; anecdotal reports say 40,000 women from the poorer parts of Poland, and beyond, are already pouring into the country, hoping to make a euro or two from cash-rich soccer fans.

Not everyone is taking this potential sex explosion lying down. Two weeks ago the Swedish Sex Equality Ombudsman demanded that the national team pull out of the World Cup, in protest at the misogynistic German plans for mobile cathouses. The Swedish FA batted away the idea, on the grounds that it would "disappoint the country".

In England, women's groups are worried about the ramifications for London 2012 Olympics; will the UK see a similar situation in six years' time?

In the shorter term, England play Sweden in Cologne on June 20 and in his crimson office on the top floor of the world's largest brothel, Armin Lobscheid is rubbing his hands in anticipation. "A man who has had sex is a happy man. We're not expecting any trouble from English lads. We are expecting profits." ·