Justice Minister Peter MacKay dodged questions Thursday from both the Liberal and NDP about whether he would send the new anti-prostitution bill immediately to the Supreme Court for a reference on its constitutionality.

A top court ruling on whether the proposed legislation passes constitutional muster could bypass years of lower- and appeals-court rulings, if the bill is challenged, before it eventually lands in the lap of the highest court.

But in question period in the House of Commons, MacKay didn't address the the queries about a possible court reference. Instead he spoke of the bill's purpose which is to help women, "exit [from prostitution] and find a better, healthier and safer life."

Last December the Supreme Court struck down most of the prohibitions against activities related to prostitution on the grounds they drove the legal act of prostitution underground and put sex workers, mostly women, in harm's way, violating their rights of security.

The court gave the government a year to come up with a new bill.

New bill makes prostitution illegal

Bill C-36, the protection of communities and exploited persons act, introduced Wednesday, makes it illegal to buy sex. It would also make it illegal to "communicate" for the purpose of prostitution in any place where a person under 18 might reasonably be expected to be present.

Critics say the new bill would force prostitutes to go to isolated locations to prevent their clients being charged, or themselves being charged if a minor is nearby, and would place them in just as much danger as the old law.

Françoise Boivin, the NDP's justice critic, told reporters in the foyer of the House of Commons Thursday, if there is no court reference, "in three or four years we'll be back to square one, in front of courts, so we'll have settled nothing."

But Janine Benedet at the University of British Columbia's law faculty doesn't think the government will ask the Supreme Court for a reference because it's not known how the police will interpret and enforce the new bill if it passes.

It's not certain how the police or the courts will determine if a location might be frequented by children, especially late at night. Nor is it clear how the bill's prohibition against advertising for sexual acts will be defined, such as whether it will include the ads found in free weekly newspapers or online.

"You need a body of evidence about how the laws are being enforced and implemented," Benedet said in a phone interview from Vancouver. "You can't just challenge them tomorrow [because] the court can say, 'Well, how can we make any decision about the impact of these laws until we know something about them?"

The government hasn't had much luck with its recent references to the Supreme Court.

Last year Ottawa asked if it could unilaterally reform the Senate, or, if it needed the consent of only seven provinces, rather than all 10, to abolish the Red Chamber. To both questions, the top court said no.

In March the court also said no to the government when it asked, in a reference, if it could amend laws so that Justice Marc Nadon, a Federal Court judge in Ottawa, could be appointed to represent Quebec on the top court bench.