TORONTO - Canada's prostitution laws place the lives of thousands of women working in a legal trade in grave danger, amounting to a form of "urban genocide," a group of sex-trade workers and advocates said Wednesday.

The Safe Haven Initiative, led by Osgoode Hall law professor Alan Young and a volunteer group of law students, is launching a constitutional challenge to strike down laws against bawdy houses, communicating for the purpose of prostitution and living on the avails of prostitution.

While there is no wording in the Criminal Code specifically outlawing prostitution, nearly all aspects of a transaction - including hiring a prostitute, scouting potential customers and making money from sex - are made illegal by those three provisions.

Young said because those laws make it illegal for prostitutes to work in their own homes or hire a bodyguard for protection, women are deprived of their right to liberty and security - a violation of the Charter of Rights and Freedoms.

"There is nothing inherently dangerous about prostitution," said former prostitute Valerie Scott, who is executive director of Sex Professionals of Canada, an advocacy group for sex workers.

"What makes it so dangerous is the way it is currently set up in this country. It's the way the laws force us to operate in totally unsafe conditions."

The situation is so dire that the laws amount to an "official death penalty" for prostitutes, Scott said.

Lawmakers and the general public must remember that prostitutes are human beings who should have equal rights under Canadian law, she said.

"So what if most of these women are drug-addicted street girls?" Scott said. "They are A, human, and B, Canadian.

"We are humans. We are part of the community. We don't come in on a shuttle from Mars every night and leave before sunrise."

Young said he felt compelled to launch the challenge and stand up for those women's rights after watching media coverage of the investigation into the disappearances of more than 60 women - mostly sex-trade workers - from Vancouver's troubled Downtown Eastside.

"As the body count was mounting, I thought, 'Somebody has to do something to stop this urban genocide,"' Young said.

The Vancouver case is an extreme example of the brutal violence often faced by prostitutes, he said, but it highlights a problem that goes much deeper.

"The reality is threats, violence and assault define the daily existence of people who work on the street in the sex trade," Young said.

The Vancouver investigation culminated in the arrest of pig farmer Robert Pickton, who was charged with 26 counts of first-degree murder and is currently on trial for six of those counts.

An Edmonton-area man is also standing trial for the killings of two prostitutes. His charges stem from Project Kare in Alberta, which looked into the disappearances of almost 80 people, many of them women in the sex trade.

Prostitution activist Sue Davis said she believes changes to the laws could have saved the lives of many murdered prostitutes.

"They target the most vulnerable of sex workers, the visible trade," she said.

"It is driving them into more and more isolated areas and making them work in more and more dangerous conditions."

A 2006 Statistics Canada report found that 171 female prostitutes were murdered between 1991 and 2004, and that 45 per cent of those cases went unsolved.

A House of Commons sub-committee concluded in December 2006 that the number of reported homicides among sex workers is "almost certainly lower than the real figures."

But after hearing testimony from more than 300 witnesses, MPs from the various parties on the sub-committee couldn't agree on legislative changes to the prostitution laws.