Lawyers for the federal government and a group of Vancouver sex workers are in Canada's top court Thursday to argue the validity of an attempted constitutional challenge to the country's prostitution laws.

Since 2007, the Downtown Eastside Sex Workers United Against Violence Society have been arguing that Canada's prostitution laws violate the Charter of Rights and Freedoms.

The group wants to challenge the laws that ban keeping a bawdy house, communicating for the purpose of prostitution, living off the avails of prostitution and procurement.

But it is not those laws that will be heard Thursday. Instead, lawyers are arguing whether the sex workers' challenging those laws in the British Columbia Supreme Court have the legal right to do so.

The federal government initially challenged the case and tried to get it thrown out of court. The government argues the sex-trade workers can't launch a Charter challenge because it doesn't qualify for public interest standing.

To qualify for public interest before the court, lawyers must demonstrate:

  • The issue is serious
  • There is no other reasonable way for the issue to come before the court
  • Those launching the case must be directly affected by it

The 2008, the B.C. Supreme Court agreed with Ottawa and denied the workers' appeal for public interest standing. But that decision was overturned in 2010, when it was appealed by the sex workers.

A decision by the Supreme Court of Canada on the issue is not expected for several months.

Supports for the sex workers' cause are expected to protest in front of the Supreme Court of Canada in Ottawa Thursday afternoon.