And despite losing an initial battle to get fines for street prostitution replaced with mandatory counselling in a draft law, MacTaggart says her war goes on.
"We don't criminalise people who sell kidneys. We criminalise the buyer."
LEGAL HOTCHPOTCH
Those who support efforts to penalise men for buying sex want to reduce prostitution by tackling demand rather than supply. If men knew more about the violence associated with the sex trade and faced more credible risk of punishment, they would be less tempted to pay for sex, the reasoning goes.
"In 15 years of interviewing prostitutes, I don't think I have ever met one who didn't at some point have a man's hands around her throat or a knife pointed at her or was beaten or raped," said Roger Matthews, criminology professor at London South Bank University and author of "Prostitution, Politics and Policy".
Sweden set the trend in Europe by outlawing paying for sex in 1999. British Home Office officials have travelled to countries including Sweden to study the laws.
Across Europe, laws vary: In the Netherlands, famed for Amsterdam's "red light" district, prostitution is legal and street prostitution is confined to managed zones, although the city wants to partially reverse full legalisation introduced in 2000, because it has not achieved its aim of bringing the profession out of the shadows and protecting sex workers.
Denmark legalised prostitution in 1999; prostitution is legal in Germany on and off the street, but coercing prostitution is an offence. In France, like in Britain, prostitution is not illegal, but touting on a public highway and pimping are offences.
The trade thrives under a hotchpotch of restrictions that evolved over years: in Britain, brothels are illegal, but "saunas" and "massage parlours", many of which are fronts for prostitution according to police, operate with licences issued by local authorities.
British society has been tolerant of prostitution for so long it will take time to make men understand that the trade is harmful to women, Matthews said.
"The UK has a very long established tradition that paying for sex is OK, it's a man's right," he said. But he said new research shows many men who visit prostitutes are not highly motivated, and could be dissuaded by penalties or education.
"They said it was like buying a curry at the grocery shop. The motivation is actually a lot lower than many people assume. They would buy sex if it was there - if it's not there, they would go do something else," Matthews said.
