Canada has become the fourth country in the world to fully authorise gay marriage after its parliament passed a contentious same-sex unions bill on Tuesday night.

The country’s Senate resounded with cheering after the vote in support of the Liberal government’s gay marriage bill, Canadian Press reported.

The bill, which passed by a vote of 47-21 with three abstentions, was approved despite bitter criticism from Canada’s opposition Conservative party, which has vowed to repeal the gay marriage law if it wins the next federal election.

The bill will become law after it receives royal assent, expected this week, CBC News reported. It passed Canadian parliament’s lower house last month.

Canada joins the Netherlands, Belgium and Spain as countries with nationally legal gay marriage. Prior to Tuesday’s Senate vote, same-sex marriage was already legal in several Canadian provinces.

More than half of Canadians support gay marriage, according to a survey released earlier this month.

But a slim majority of the 1,000 people surveyed said they opposed adoption rights for same-sex couples.

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