Bitterly divided federal Liberals did not willingly become trailblazers. The government was forced to act after a series of court rulings struck down marriage laws. Courts in Ontario, Quebec and B.C. have ruled that the exclusion of gays and lesbians unjustifiably violates equality rights.
Chretien will try to assuage some outraged members of his own caucus by allowing religious institutions to decide which marriages they will sanctify.
''We'll be proposing legislation that will protect the right of churches and religious organizations to sanctify marriage as they define it. At the same time, we will ensure that our legislation includes and legally recognize the union of same-sex marriage.
''As soon as the legislation is drafted, it will be referred to the Supreme Court. After that, it will be put to a free vote in the House of Commons.
Legislation covering the changes will be ready in just two weeks - an unusually speedy drafting period for such contentious legislation.
''We don't want there to be a long period of uncertainty,'' Chretien said after a cabinet meeting. ''We want to complete this file and deal with it as quickly as possible, and as soon as we have the reference then the House of Commons will vote.''
Recent court rulings striking down traditional marriage laws effectively forced the government's hand.
Courts in Ontario, Quebec and British Columbia have ruled that the exclusion of gays and lesbians unjustifiably violates equality rights.
Ottawa was already preparing its response to those verdicts when it was hit two weeks ago by a bold ruling in the Ontario Court of Appeal.
The court declared marriage laws unconstitutional - effective immediately - and forced Ottawa to either fight the ruling in court or move to re-write the traditional laws governing matrimony.
Deputy Prime Minister John Manley said the government accepts same-sex marriage as an inevitable and irreversible fact of modern society.
''I think on balance people recognize that the decisions of the courts are really pointing in a direction from which it would be difficult - if we wanted to - to turn back,'' Manley said after stepping out of a meeting where his cabinet colleagues were still discussing the divisive issue.
''I think that's a recognition of the fact that society has changed. The courts have recognized it and government needs to recognize it as well.''
Gays and lesbians in Ontario had refused to wait for Ottawa to decide. They began marrying immediately after the court decision, profiting from a sudden available right denied to them throughout most of human history.
Governing Liberals have been bitterly divided over the issue. Several members of Chretien's caucus were openly and ardently demanding he order an appeal to the Supreme Court of Canada to protect the traditional view of marriage.
Alberta Premier Ralph Klein warned that his province would invoke the controversial notwithstanding clause in the Constitution should a Supreme Court ruling favour same-sex marriage.
The controversial clause allows governments to supersede parts of the Charter of Rights and Freedoms for a five-year period.
The historic view of marriage as a heterosexual institution was thought to be so obvious that it was never explicitly included in federal statutes until recently.
It only became enshrined in federal law in recent years, including a 2000 bill that extended full federal tax and social benefits to same-sex couples.
That Modernization of Benefits and Obligations Act begins with the following preamble: ''For greater certainty ... the meaning of the word 'marriage' ... is ... the lawful union of one man and one woman to the exclusion of all others.''
Gays and lesbians were not satisfied by the changes.
They argued that current laws have resulted in a patchwork of inequality from coast to coast, as some provinces extend full benefits while others don't. And, they argued, the issue at stake is human rights.
Gay-rights advocates abhor the traditional restriction as an implicit suggestion that homosexuality is shameful and not worthy of equal footing.
Federal lawyers were forced to fight a series of court challenges while Ottawa prepared its own stance on same-sex marriage.
The House of Commons justice committee held public hearings across the country while preparing for what was expected to be a landmark report on same-sex marriage.
The Liberals released a consultation paper last November offering several options.
They included changing the definition of marriage to allow inclusion of same-sex couples; creating civil unions to allow a parallel legal recognition for homosexuals; leaving the definition of marriage solely in the hands of religious institutions.
Note: Source: Canada.com