Conservative delegates took the first step towards changing the party's policy on same-sex marriage at the party's convention in Vancouver Friday.

A resolution to ticket rather than criminalize small amounts of marijuana also passed its first vote, but another to support medically assisted dying failed at the session focused on criminal justice and social policy.

"I think I'll look back on this moment in my political career, in my life, as something that was really transformative and really awesome," MP Michelle Rempel told reporters after the vote, her voice breaking after having shared with delegates her family's connection to the issue.

"I'm having a hard time finding words. There's not a lot of talking points for this situation, but I'm very happy and I'm very proud."

BREAKING NEWS: Definition of marriage motion has made it - it will be debated in Saturday plenary at <a href="https://twitter.com/hashtag/cpc16?src=hash">#cpc16</a>. Waiting for full list still. —@janycemcgregor

It was standing-room only and the atmosphere was tense as delegates raised their cards to vote. Some accused others of not respecting the rules.

The vote was 297-143 in favour of the motion to remove the definition of marriage as being between one man and one woman from the party's policy book.

That margin proved sufficient to see the proposal move on to a final vote at Saturday's plenary session with all delegates.

The party was set to announce later Friday the full list of 30 proposals which have advanced, based on the level of support each received in the preliminary breakout sessions.

Took vote for granted?

Delegates lined up at the mic to speak both for and against the motion, with the first proponent urging the room "let's make history."

Saskatchewan MP Brad Trost warned of how divisive it was. There would be consequences electorally, he said: social conservatives would abandon the party. Without the support of this part of the Conservative base, Liberals and the NDP get "a walk to power."

After the vote, delegates left the room buzzing over the outcome. Trost and Rempel spoke to reporters, but side by side in an apparent show of unity amid disagreement.

"Discussing the fundamental rights of human beings is not the place for politics," said Rempel firmly. The debate on this was settled over 10 years ago when Parliament voted, she said.

"My side probably took this for granted," Trost said. "We'll see what happens if it makes it to plenary."

"I'm campaigning as a defender of traditional marriage. Period," he said. But he'll continue to work with his caucus colleagues that disagree. "I'm not walking away from my party," he said.

Trost also linked the issue to the party's leadership race.

"I like [candidates] Max [Bernier], I like Kellie [Leitch]. But those two were in there actively supporting this. I'm sorry, but those two are off my list now," Trost said.

He said he might support someone like (as yet-undeclared candidates) Jason Kenney or Andrew Scheer instead, because he knows them to be more like-minded.

However, Kenney said on CBC News Network's Power & Politics that he supports the motion and that the issue "is done, it's over. We have same-sex marriage as part of Canadian law and policy declaration, in my judgment, should reflect that new reality."

Ontario MP says she supports removing her party's definition of marriage as the union of one man and one woman 6:27

"We are the party of equal opportunity. We are the party that is inclusive," Leitch said in Vancouver. "I'm delighted that this resolution passed today at the plenary so we can move forward."

"This is a fabulous moment," she said.

The third declared leadership contender, Michael Chong, told CBC News Thursday he is also supportive of the proposal. It moves the party to a neutral position, he said, allowing it to include those on both sides of the issue.

All the party's leadership contenders — declared and undeclared — were onstage Friday afternoon speaking to delegates in a special showcase to mark one-year mark out from the party's leadership election.

Pot vote passes, assisted dying fails

The debate over ticketing, rather than arresting, those found with small amounts of marijuana, also found a good debate.

Former cabinet minister and police chief Julian Fantino told delegates police have been begging for this to happen. In the end the vote carried, but by a smaller margin than the marriage vote: 158-116.

That margin proved insufficient to make the cut to reach the final plenary on Saturday.

Interim Conservative leader Rona Ambrose, seen here during a tv interview Friday, sought to avoid a divisive policy debate on abortion at the 2016 policy convention, according to a conservative news website. (Jonathan Hayward/Canadian Press)

On other proposals, delegates voted 177-103 in favour of a motion to condemn gender-selection abortions and 184-59 in favour of conscience rights for medical practitioners asked to perform abortions or assisted suicide against their beliefs.

But another motion to support assisted dying was defeated and will not advance.

Delegates also very enthusiastically supported a proposal that called civilian gun ownership a "Canadian heritage" and was amended to call for a review of all non-essential gun laws.

Warnings about becoming 'Liberal light'

In a release Thursday, Charles McVety, the head of the 148,000-member Institute for Canadian Values lobby group, warned Conservatives who had previously sought the support of his organization were about to renege on commitments to uphold key principles.

Meanwhile, a group of prominent Conservatives, including former Canadian Alliance leader Stockwell Day and Ontario Progressive Conservative Leader Patrick Brown, are set to discuss developing new policy positions on climate change later Friday.

"The folly of becoming a 'Liberal light' party is it leads to complete and utter failure at the ballot box," the release from McVety's group said. "If conservative grassroots don't like the party platform, they don't vote."

A report last month in The Interim, an online news site dedicated to issues dear to the social conservative cause, said a motion about regulating abortion services was rejected by the party's national policy committee following a direct and last-minute appeal by interim leader Rona Ambrose.

The website reported that Rempel told the committee there was "no place for me in a Conservative Party that opposed abortion." Rempel was elected to the policy committee as the southern Alberta representative, according to her office.

Friday's policy debates represented uncharted territory for the party: policy debates free from the influence of former leader Stephen Harper — or any permanent leader, for that matter.

Supreme Court decisions are forcing the party's hand on matters like assisted dying, noted Ontario MP John Brassard.

"We can continue fighting them, but the reality is, the train has left the station," he said.