Ontario's Appeals Court began a week of hearings Monday in a landmark case that will decide if three anti-prostitution laws are constitutional.

A lawyer for the Attorney General of Canada presented arguments for the federal and provincial government's case, contending that the sex trade itself is dangerous to women, not the laws aimed at curbing it.

Ottawa's lawyer, Michael Morris, said that violent pimps and johns are the key safety hazard in the sex trade. He argued that because the act of engaging in the sex trade is not constitutionally protected, there should be no obligation to maximize the safety of prostitutes.

In response, Justice David Doherty said he found it hard to understand "why it's not self-evident that these provisions harm the ability to carry out prostitution safely."

Morris argued that the laws don't contribute to violence against prostitutes but protect them. The violence that a prostitute suffers come from multiple factors, none of which relate directly enough to the laws to justify striking them down, he said.

What the case comes down to is whether or not these laws contribute to harms sex-trade workers face, Morris said.

"This is a violent world (and) the law can't be held responsible for tenuous connections," he said.

The federal and provincial governments are appealing a ruling made last year that struck down laws that prohibited keeping a common bawdy house, communicating for the purposes of prostitution and living on its avails.

Ontario Superior Court justice Susan Himel determined the laws were unconstitutional, saying they force prostitutes to work in unsafe circumstances. That ruling was put on hold to give the federal and provincial governments a chance to appeal.

Groups representing prostitutes say the laws prevent them from working indoors, hiring drivers and bodyguards, and taking time to assess a potential client before agreeing to provide their services.

Sex-trade workers say it would be safer for them to work indoors, hire bodyguards and take the time to talk with a potential client to asses their risk potential.

One of the women who challenged Ontario's anti-prostitution laws is dominatrix Terri-Jean Bedford. Bedford said that the current laws force her to work in unsafe conditions.

"We are here today to gain new laws, civil liberties, human rights, freedom of expression for all Canadians, whether you like it to not," she told reporters outside the courthouse on Monday.

Others, including the Canadian Association of Sexual Assault Centres and the Native Women's Association of Canada, say legalization of prostitution would further victimize vulnerable women. Religious groups argue it will subject society to immoral behaviour, while the governments say prostitution is a "high-risk" activity that no one is obligated to engage in, and no government is obligated to protect.

CTV legal analyst Steven Skurka said the argument hinges on whether current laws violate the Canadian Charter of Rights and Freedoms by forcing sex workers to choose between their liberty and their security.

"There's no question that it's dangerous work," Skurka said on Sunday. "The question is whether these laws create that danger."

The Canadian Civil Liberties Association, sex-work advocacy group Maggie's, the Canadian HIV/AIDS Legal Network and the Christian Legal Fellowship are among 19 groups represented by seven interveners in the case.

Arguments begin on Monday and are scheduled to last the week, held in front of a panel of five justices.

The decision could decriminalize prostitution in Ontario and affect laws across the country by setting the stage for legal challenges in other jurisdictions.

With files from CTV Toronto's Michelle Dube and The Canadian Press.