A million German men visit prostitutes each year

Germany's Women and Families Ministry estimates that turnover from bars, clubs and brothels connected to prostitution is in the region of $4.5bn per year.

But while some prostitutes actually pay tax on some of that money, sex workers have routinely been denied access to state health insurance and pension schemes.

In the past, most prostitutes were forced to register as housewives in order to qualify for these schemes, and that will now change.

Contracts

Pimping - the practice of employing prostitutes - becomes legal, provided there are formal contracts and the women enter the deal willingly.

Forcing women to sell sex, using child prostitutes and trading in women or children will remain strictly illegal.

Prostitutes will now be able to sue their clients for non-payment if they can identify them.

But the men themselves will have no legal recourse if they are not satisfied with the service.

Not impressed

Most significantly, the law says that prostitution is no longer to be seen as immoral.

But prostitutes' groups are not impressed.

One academic expert - Regina Laser - says it will help a small number of German prostitutes working from bars and brothels.

But she believes the law will be catastrophic for street workers, the vast majority of whom are foreign and often illegal immigrants.

Church groups and conservative politicians have already voiced their opposition to the change.