After years of acrimonious debate, the issue of same-sex marriage is finally coming to a legislative head.

When lawmakers wrap up debate on Bill C-38 -- which would legalize same-sex civil marriage countrywide -- they'll face the tough task of voting on it.

To become law, the bill will need the support of at least 154 MPs. Considering the fact the minority Liberal government controls just 135 seats -- not to mention estimates that close to one-half of Liberals are either opposed or undecided -- passing the bill into law will require the support of opposition MPs.

So, with that in mind, CTV.ca surveyed the parties to determine not only where they stand officially, but to also gauge the level of unity within their ranks.

Liberal Party

According to the federal Liberal platform, "Moving Canada Forward," the governing party views equal marriage as an issue of human rights.

"Respecting our diversity includes ensuring we respect basic human rights for all, including gays and lesbians... We will not invoke the "notwithstanding clause" of the Charter to deny equal rights, nor will we obligate religious institutions to conduct marriage ceremonies that contravene their own beliefs and practices."

As such, Prime Minister Paul Martin has told anyone who'll listen that the move to change the law will grant equal rights to a minority -- without trampling on the rights of religious institutions

For Martin, a practising Catholic, coming to that conviction was a difficult journey.

"Sometimes it is up to governments to lead," Martin said in his year-end interview with CTV. "I believe ultimately, this is a Charter right and I think that that view is the one that is going to predominate."

Now that he's there, he won't budge -- even if it means risking his minority government.

"It's not my intention to go into an election. We want to govern," Martin said during a recent Asian trade mission.

"Am I ready to go into an election to uphold the charter of rights against those who would attack it? The answer is certainly yes."

Despite talk of a free vote, when it comes down to it, Martin has said he expects all of his cabinet ministers and parliamentary secretaries to support the bill.

At least two cabinet ministers appear undeterred by the threat, however, with Northern Development Minister Joe Comuzzi and Natural Resources Minister John Efford both hinting they might break ranks on the issue.

Backbench MPs, on the other hand, will be allowed to make up their own minds. According to a Globe and Mail survey published in early February, as many as 30 are undecided with at least 25 firmly opposed.

Ontario MP Pat O'Brien is one of the backbenchers unafraid to express his dissent.

"I will use every single possible peaceful democratic tactic I can think of to defeat this legislation," he told CTV.

The Conservative Party

In the Conservative Party's latest platform, "Demanding Better," the Official Opposition made clear it was dissatisfied with the fact courts have taken the lead on the issue.

"The Conservative party will fight to give a greater voice to Parliament," the platform said. "We will ensure that issues like marriage are decided by Parliament, not the courts."

More recently, ads placed by the party in ethnic newspapers countrywide distinguished Martin and Harper's personal positions.

"Paul Martin wants to impose same-sex marriage. Stephen Harper believes in traditional marriage. We'd like to know where you stand," the ad read.

Harper, who has repeatedly stated his personal belief in marriage as the unique union of a woman and a man, has called the move to legalize same-sex a first step down a slippery slope.

"I believe we have to recognize the traditional definition of marriage in law, otherwise we will continue to be presented with demands that just get more and more radical," Harper said.

"I don't believe there's any support in the country for the recognition of polygamy in law."

Nevertheless, Harper has also called for a free vote on the matter -- and even acknowledged inevitable dissent within his party ranks.

"I've taken a position with the backing of the majority of caucus and party members," Harper said in January. "I fully expect that any member of the party who disagrees with that position will become a media star."

So far, at least five members of the Conservative caucus have taken him up on the offer, including his former leadership rival, Ontario MP Belinda Stronach.

"I believe that Canadians have the right to be treated equally under the charter," Stronach said. "I believe you can't pick and choose when it comes to the Charter of Rights."

Other Conservatives who have openly declared their plans to support the bill include Nova Scotia MP Gerald Keddy, B.C. MP James Moore and Calgary MP Jim Prentice.

"It's a question of individual liberty," Prentice said.

"What moral authority do we as a society have to say to those fellow citizens that you're not entitled to the same things we are, which is a civil marriage licence. As fellow citizens, they're entitled to the same rights from government as I am."

The NDP

In its party platform, the federal NDP said same-sex marriage is a question of equality rights.

"Canada's NDP will respect equality by … recognizing the equality of loving adult partnerships by extending civil marriage equality to same-sex couples, while respecting each religion's right to determine its own definition of marriage."

The issue is so fundamental, in fact, that leader Jack Layton has made it clear since 2003 that his MPs won't be allowed a free vote when it comes to the equal marriage bill.

"We have a party policy and it is to support this legislation and that's the way it's going to be," Layton told reporters at an NDP caucus retreat that year.

Layton has since made it clear his views have not changed -- telling reporters, "I believe, on balance, (the party position) is fair and consistent with what we tell voters we believe."

But there's still at least one dissenting voice within the NDP ranks.

Citing her conscience, and the views of her Churchill, Manitoba constituents, MP Bev Desjarlais has vowed to defy the party whip and vote against the legislation.

When asked last month about the option of skipping the vote, and thereby avoiding open defiance of her party, Desjarlais was dismissive.

"I believe as an elected representative, there are issues that people want to see you vote on one way or the other," she said.

The Bloc Quebecois

Although the party has no official same-sex marriage policy, the Bloc Quebecois has consistently stated its support for same-sex marriage legislation. Acknowledging the bill as a difficult moral issue, leader Gilles Duceppe has promised a free vote for his MPs.

According to Duceppe, there is little room for debate.

"It's clear that we're talking about civil marriage, not religious marriage, that the state has no business imposing its rules on churches, and that the religion of some shouldn't become the law for all. We clearly see that's the goal of this law, and I support that."

His party is expected to express that support when it comes to a vote -- and that means a potential 54 votes that could prove crucial in light of the minority distribution of seats in the House of Commons.