Manitoba has become the fifth jurisdiction in Canada to legalize same-sex marriage.

Court of Queen's Bench Justice Douglas Yard ruled Thursday morning that the current definition of marriage in provincial law is unconstitutional.

"The traditional definition of marriage in Manitoba is reformulated to mean a voluntary union for life of two persons at the exclusion of all others,"  Justice Yard said in his decision.

Gay rights groups say they expect the first same-sex wedding to be performed in the province by the end of the week.

The case was brought forward by three same-sex couples who argued for the right to marry.

The couples sued the provincial and federal governments asking that the definition of marriage as a union of a man and a woman be declared contrary to the equality provision in the Canadian Charter of Rights and Freedoms.

Lawyers for the federal government, which has jurisdiction over the definition of marriage, did not oppose the motion. It's the first time that federal lawyers did not try to fight or adjourn a court battle over same-sex marriage.

Lawyers for the Manitoba government also offered no opposition.

Gay marriages are already legal in Ontario, Quebec, British Columbia and Yukon, after judges in those provinces declared the definition of marriage unconstitutional.

Same-sex couples were legally given the right to marry in the Yukon at the end of July.

Justice Yard said those precedents weighed heavily in his decision Thursday.

"The cumulative effect and the overwhelming effect of that judicial authority is to the effect that the traditional definition of marriage is no longer constitutionally valid in view of the provisions of the Charter of Rights and Freedoms," he said.

The Supreme Court of Canada will begin holding hearings on the federal government's draft legislation to legalize same-sex marriage across the country.