The Canadian Government is to push for the legalisation of gay marriages following a series of critical court rulings on the subject.
Mr Chretien is following court rulings
Prime Minister Jean Chretien said on Tuesday that the new legislation will not however force churches to recognise same-sex partnerships.
But, he added, "we will ensure that our legislation includes and legally recognises the union of same-sex couples", the Globe and Mail newspaper reported.
The bill is likely to face strong opposition from within Mr Chretien's governing Liberal party and from the conservative province of Alberta.
Mr Chretien said he will allow legislators to vote as their consciences dictate on the bill, which he promised would be ready by autumn.
He said he would refer it to Canada's Supreme Court to avoid "uncertainty".
The announcement follows a ruling by a court in the province of Ontario last week essentially ordering the government to change the definition of marriage.
Courts in Quebec and British Columbia have also ruled in favour of gay marriages this year, but the Ontario ruling last week was much more forceful.
Couples started marrying immediately after the Ontario decision
The 61-page ruling said defining marriage to include only heterosexuals violates gay couples' rights under the country's constitution, the Charter of Rights and Freedoms.
Polls indicate a slight majority of Canadians favour legalisation of same-sex marriages, our correspondent says.
Some Anglican churches in Canada have already offered blessings to gay and lesbian couples.
Belgium and the Netherlands recognise gay marriages.
Several other European countries grant same-sex couples at least some of the same rights as married heterosexual ones.