Canada is poised to become the third country in the world to legalise gay marriage. Prime Minister Paul Martin announced he would proceed with the controversial legislation last week, after the Supreme Court of Canada said that parliament had the constitutional right to broaden the definition of marriage to include same-sex couples.
"Several centuries ago, it would have been understood that marriage be available only to opposite-sex couples," the judges said. "The recognition of same-sex marriage in several Canadian jurisdictions as well as two European countries belies the assertion that the same is true today."
Gay marriage is now legal in Belgium and the Netherlands. In Canada, gay couples can already marry in six provinces and one territory, thanks to lower court rulings that said the traditional definition of marriage violated Canada's Charter of Rights and Freedoms. If the federal legislation passes, it will mean that gay couples across the country will have the same right.
The bill will apply to civil, not religious ceremonies. Churches which oppose gay marriage will not be forced to perform them.
In the past, Mr. Martin has expressed misgivings about the state sanctioning gay marriages. It was under his predecessor, former prime minister Jean Chretien, that the Liberals drafted the bill and referred questions about it to the Supreme Court. Prime Minister Martin, a Roman Catholic, was under pressure from the church not to abandon the traditional definition of marriage as a union between a man and a woman.
"This was not an easy decision for me," Martin told reporters after the Supreme Court released its non-binding opinion. "It is one that I've struggled with, but fundamentally it comes down to the equality rights under the Charter. "I do not believe you can have two classes of citizen."
He has promised to introduce legislation early in the new year.
Civil rights and gay and lesbian groups and couples cheered the news.
"It's really great to be in a country that thinks our relationship is the same as everybody else's," Amy Swensen, 26, told the Canadian Press wire service. She is planning her wedding with Sandra Tiano, 33. Both live in Alberta.
Alberta is one of the hold-out provinces, and its premier, Ralph Klein, says he is disappointed the Supreme Court left his province with few legal options.
"There is very little legally we can do about it, but there is a lot politically."
He is calling for a referendum on gay marriage, as are other religious or socially conservative groups. They are planning lobbying campaigns to get their members of parliament to vote against the legislation.
Reverend Charles McVety, president of the Canada Christian College in Toronto, described the decision to legalise same-sex marriage as "catastrophic".
"Marriage is being hijacked today and I'm very sad about it."
Mr Martin, who heads a minority government, will allow a free vote among ordinary members, but cabinet ministers will have to vote with the government in favour of the bill. Gay marriage appears to have the support of many MPs in two of the three opposition parties, so will likely pass even if some Liberals vote against it.
Meanwhile, gay and lesbian activists are moving on to the next marital frontier - the right to divorce. The Ontario Superior Court recently declared that the federal Divorce Act was unconstitutional because it defined a spouse as a "a man or a woman who are married to each other".
There are about 3,000 newly married same-sex couples in Canada, and outside of Ontario, it is unclear how those unions will legally end should the bloom come off the rose.