Canada's Hutterite community has taken an unprecedented political stand, writing the prime minister to warn that the country could become the next Sodom and Gomorrah if same-sex marriage is legalized.
Hutterian Brethren Church of Canada, which represents about 50,000 Hutterites in British Columbia and the Prairies, urged Paul Martin not to adopt the proposed legislation.
"We will be classed as traitors in God's eyes, and we will live the darkest day in all of Canada's history," says the letter.
Never before have the intensely private Hutterites taken such a public, and political, stand. The religious sect tries to maintain political neutrality and its members do not usually vote in elections.
The letter shows how outraged many Hutterites are by the proposed legislation.
"Two men living together is not right: we are totally against that," Paul Hofer, an elder at the Arm River Hutterite Colony in Saskatchewan, told CBC News.
"There's only going to be one judge over that one...and that's our dear Lord up in heaven."
Joseph Wollman, who lives in Hillcrest Hutterite Colony near Saskatoon and was one of the authors of the letter, said the Bible forbids same-sex relationships.
"It's a terrible sin. If all the people on the Earth would turn that way, the people in the world would die out," Wollman told the CBC.
Catholic and Sikh organizations in Canada have also come out against the marriage change.
However, the Mennonite Church of Canada has said it will accept the change as long as the legislation allows religious groups to decide for themselves whether they will wed same-sex couples.
A recent Compas poll suggested that two-thirds of Canadians would prefer a referendum on the issue of same-sex marriage instead of a parliamentary vote.
The Hutterites would also prefer a referendum.
The legislation went through its second reading in the House of Commons on Wednesday.