As legal arguments continue into a challenge of Canada's prostitution laws, those who oppose the sex trade say the current laws are actually the best way to protect prostitutes.

Joanne McGarry of the Catholic Civil Rights League, one of the groups that has been granted the right to legally intervene in the case, says effectively decriminalizing prostitution would not end violence against prostitutes.

"There are risks inherent to the occupation that don't relate to whether it's legal or illegal," McGarry told Canada AM Wednesday.

"In a certain percentage of cases, there will always be people attracted to prostitution for the purpose of dealing harm. I think the laws we have now provide the police with some means for reducing that harm."

A lawyer for three sex-trade workers is before an Ontario Superior Court judge this week to argue that Canada's laws that outlaw "communication for the purposes of prostitution", "living off the avails of prostitution", and "keeping a bawdy house" put prostitutes in danger they ply a trade that the courts have deemed legal.

Alan Young, the Osgoode Hall law professor representing the women, argued in court Tuesday that with the way the laws stand, prostitutes can't ask the questions needed to screen potential clients, they can't work together in brothels, and they can't have anyone protect them. That leaves sex workers forced to work on the streets where they are vulnerable to the violence.

In court Tuesday, Young said there have been many "shocking and horrific" stories of women who work the streets since the laws were enacted in 1985, most notably the case of Robert Pickton, who is suspected in the murder of at least 26 prostitutes.

"There are dangers working on the street. (The law) has contributed to the lack of safety and harm women face," he told reporters outside the Toronto courthouse where the case is being heard.

Young also disagrees with those who argue prostitution is inherently unsafe.

"Obviously, it is safe when conducted indoors," he told CTV News Channel Tuesday. "International studies in legalized jurisdictions have shown that. So it's common sense to say it's safer to move indoors."

But McGarry questions whether changing the current laws would make prostitution any safer. She doesn't think allowing sex workers to practise their trade in a brothel or with the help of a pimp would make it any safer.

For instance, she says, if someone is being forced into the sex trade by a pimp or through human trafficking, current laws allow police to arrest that pimp. 

"The laws we have now offer the means to provide help to those in the business who don't wish to be in it," she said.

"People don't choose to become prostitutes the same way they choose to become school teachers or office workers or sales reps," she added. "A great many are acting under coercion and sometimes against their will, and I don't think we're going to improve that by turning pimp into a legal occupation."

Instead of making it easier for prostitutes to operate, we should be working on stopping people from entering the business at all, McGarry argued.

"We should be looking for ways to give people dignity so they don't engage in prostitution," she said.

The Crown is expected to argue that decriminalizing prostitution could cause women to view it as "a career choice," make Canada a haven for sex tourism, and perhaps lead to "red-light districts" across the country.

They also plan to argue that prostitution is inherently degrading and unhealthy, and should not be encouraged by lax laws.

"The Charter does not mandate Parliament to design a regime allowing the applicants to earn money by engaging in prostitution with fewer hindrances," federal prosecutor Michael Morris said in a legal brief.

Evidence in the case is expected to consist mostly of affidavits from 56 individuals, including sex workers, police officers, academics and NDP MP Libby Davies, whose Vancouver riding includes the Lower East Side.

Arguments are scheduled to be heard through Thursday; a decision in the case could take months.