A Liberal Member of Parliament has reiterated his view that allowing gays and lesbians to marry could open the doors to polygamy.

Pat O'Brien's comments were made amid the emotional and sometimes acrimonious debate coming from House of Commons justice committee hearings to examine legalizing same-sex marriages.

The committee is trying write a report all members agree on, after travelling across the country to hear Canadians' views on redefining marriage to include gay and lesbian couples.

"Don't tell me Ralph and Bob being together is marriage because to me it's just wrong," O'Brien told CBC Radio.

"If you're going to throw open the definition of marriage so you destroy it in essence, how do you know you can ever draw the line any place? If I want two or three wives and want that considered legal marriage, who are you to tell me I can't do that?"

One of O'Brien's Liberal colleagues on the committee, Marlene Jennings, said the federal government has no choice but to widen the definition of who should be considered as married.

Jennings, who represents the Montreal riding of Notre-Dame-de-Grâce-Lachine, said she's hopeful she'll be able to convince other committee members to support such a change.

Earlier in the week, Conservative deputy leader Elsie Wayne stood in the Commons and attacked the notion of gay and lesbian marriage.

"If they are going to live together, go live together and shut up about it," she said.

O'Brien, the Liberal member for the London-Fanshawe riding, told the CBC in an interview Friday it would be best to keep the issue moving up through the courts.

He said the Supreme Court will probably rule gays and lesbians should be allowed to marry. In that case, he would prefer the government use the Constitution's "notwithstanding" clause to preserve the traditional definition of marriage as being as a union between a woman and a man.

The justice committee must report to Justice Minister Martin Cauchon on the issue by next month.

Earlier this month, the B.C. Court of Appeal ruled that preventing gay couples from marrying is discriminatory. Ottawa hasn't said yet if it will appeal.

Similar decisions have been made by courts in Quebec and Ontario. Ottawa is appealing those.

If Ottawa doesn't appeal the B.C. ruling, it faces a deadline of July 12, 2004, to change the law defining marriage to make it non-discriminatory to same-sex couples.