Canada's prostitution laws are being put to the legal test in a London, Ont. courtroom where two people are charged with advertising sexual services, profiting from the sex trade and producing a person to offer sexual services.

The first defence expert witness called in the case, academic Chris Atchison, testified that the new law, often referred to as Bill C-36, makes it less safe for people in the sex trade to do their jobs.

Sex workers are not victims, Atchison says. They become sex workers because they want money, he says. The new legislation turns the client/worker relationship into an antagonistic one, Atchison says. —@KateDubinski "I believe the application of these laws makes things worse for the most vulnerable people on the street but also for others in the sex industry," Atchison told the court.

The case before the court is that of Hamad Anwar and Tiffany Harvey. They face more than two dozen sex-related charges each, including making money from the sex trade, advertising sexual services, and forcing someone into the sex trade.

The charges relate to a bust made by London police at an escort service in November 2015.

The accused are being represented by well-known Toronto lawyer James Lockyer.

Lockyer doesn't dispute that his clients ran an escort agency. But at issue in Tuesday's proceedings are three charges under Canada's three-year-old prostitution law, often referred to as Bill C-36:

Advertising someone else's sexual services

Benefiting financially or otherwise from someone else's sexual services

Procuring a person to offer a sexual service (a charge that can be laid against a pimp, for example).

Lockyer declined several interview requests from CBC News.

'We always knew there would be a constitutional challenge'

Experts have predicted it was only a matter of time before Canada's three-year-old prostitution laws, contained in Bill C-36, were challenged.

The new laws criminalize the advertising and buying of sex — but decriminalize its sale.

Proponents say it's the right model because it punishes people who buy sex, not those who sell it.

But opponents say the laws force sex work further underground and criminalize advertising sex, which allows those in the sex trade to screen their clients ahead of a meeting.

"Prostitution is male violence against women, which is a serious barrier to gender equality and is incompatible with the internationally-accepted principles of human rights," said Megan Walker, the executive director of the London Abused Women's Centre.

"We always knew there would be a constitutional challenge. I think it's good to have some closure on this, although I recognize that getting to the Supreme Court could be years away. It will highlight the issues and I am confident that at the end of the day, the ruling will stand."

Canada's new prostitution laws were passed at the end of 2014.

'Radical feminists versus harm reduction'

On the stand, Atchison characterized the deep divide among those who are for and those who are against the country's new prostitution laws, also known as the Nordic Model, as a difference of opinion between "radical feminists" and those advocating for "harm reduction."

A witness who will testify for the Crown, Maddie Coy, "comes at this from the vantage point of seeing the sex industry as an institution of the patriarchy, and prostitution as violence against women. It's the prohibitionist, radical feminist perspective," he said.

Others, such as Atchison himself, see sex workers as "making choices and engaging in labour."

Studies that show that the sex industry has shrunk in Sweden, which has similar laws to ones enacted here, are conducted by people who have a vested interest in the laws succeeding, and don't reflect reality, Atchison said.

"The fact that there are fewer street sex workers could be attributed to technology. They went off-street with the use of cell phones and the Internet. We've seen a steady decline in the number of people working on the street for the last 20 years."

The court case continues Tuesday afternoon.