OTTAWA — The Liberal government has stacked the parliamentary deck in favour of its same-sex marriage bill by naming only supportive Liberals to a key committee.

The makeup of a new same-sex committee should ensure Bill C-38 doesn't suffer any major changes before it arrives for a final vote in the House of Commons in the coming months. Although the controversial marriage issue has divided the ranks of the governing party, it will be a powerful block of six Liberals sitting on the committee scrutinizing the bill.

Every single one of them has stated their support for same-sex marriage, raising some eyebrows from Liberals who disagree with the legislation.

"The odds are about as stacked as they could be," said Ontario Liberal MP Pat O'Brien, a vocal opponent of the legislation.

"The committee might have benefited by hearing from at least one Liberal who disagrees. That might have added something to the debate."

But one Liberal member of the committee said the group's composition should come as no surprise.

"If the government proposes a bill, obviously the government wants its bill to pass," said MP Don Boudria.

"If you buy tires for your car, don't you want them to work? And if they didn't why would you buy them? It's not rocket science."

The committee's composition underscores just how committed the government has become to the same-sex cause, a far cry from last year when Prime Minister Paul Martin avoided taking a public stand on the issue.

The government has promised backbench MPs a free vote on the legislation but has made it clear that it considers Bill C-38 a human-rights matter.

Liberal brass canvassed caucus members for their position a few weeks ago, and only certain Liberals were contacted when it recently came time to create the committee.

The 13-member committee has nine MPs -- including two from the Bloc Quebecois and one New Democrat -- who support redefining marriage, and four Conservatives who oppose it.

Within weeks, the committee will start studying each of the bill's 15 clauses and ultimately decide whether it should proceed without amendment for a final vote in the House of Commons.

The final vote could be close but it is expected the Commons will approve the legislation.

A gay-rights website tracking MPs' public statements (marriagevote.ca) says 164 of the 308 MPs have expressed their support, 134 their opposition and nine are listed as undecided.

Justice Minister Irwin Cotler hopes the legislation passes before the Commons recess in June.