Voters in Canada's oil-rich Alberta province will decide Monday whether to launch a process that could eventually lead to independence, testing national unity as US President Donald Trump's trade war and threats to make Canada the 51st state have strengthened Canadian patriotism.

Monday's vote is not a direct referendum on independence. Instead, Albertans will decide whether to remain a province or begin the legal process toward a future referendum on separation. Alberta holds most of Canada's proven oil reserves, the fourth-largest in the world.

More than 1.35 million Albertans, representing 43% of eligible voters, cast advance or special ballots ahead of Monday's vote, far exceeding the 810,000 who voted early in the 2023 provincial election.

Even if voters reject the proposal, separatist leaders say the movement, which has grown from a fringe cause into a significant force in provincial politics, will continue.

Canadian Prime Minister Mark Carney urged Albertans not to take the outcome for granted, calling for a decisive result as he concluded two days of campaigning in his home province.

"Vote like Canada's future depends on it because it does," Carney told a pro-Canada rally in Edmonton on Friday, where he grew up.

The vote also comes as Alberta mourns four service members killed in a fire at Canadian Forces Base Wainwright over the weekend. Another 39 people were injured, including 19 critically, during military training. Carney described the incident as one of the worst peacetime tragedies involving Canada's military on domestic soil and ordered flags lowered to half-staff nationwide.

Alberta Premier Danielle Smith, who called the referendum despite opposing independence, recently cited a poll showing that only 22% of Albertans supported separation, a figure she said was still too high.

Carney draws cheers with calls to diversify trade

Carney received his loudest cheers at rallies in Calgary and Edmonton when he spoke about reducing Canada's trade dependence on the United States. The enthusiastic response highlighted how Trump's trade war and threats of annexation have fuelled Canadian nationalism, even in traditionally conservative Alberta.

Carney has emerged as an unusually popular figure in the province, where Liberal prime ministers have long faced resentment over federal energy policies.

He has adopted a more energy-friendly approach, backing a proposed oil pipeline to the Pacific Coast and joining Smith in opposing Alberta's separation from Canada.

Carney warned that the referendum was taking place at the "worst possible time" and urged Albertans not to use their votes simply to send a message to the federal government in Ottawa.

Smith, who frequently clashed with former Prime Minister Justin Trudeau, praised Carney for improving relations with Alberta.

"I think what we can agree on is that we have had some real change in the last 18 months," she said Friday.

Smith opposes separation despite pressure from party activists

Smith called the referendum despite opposing independence, reflecting pressure from separatist activists within her governing United Conservative Party who helped bring her to power. Some of the activists also helped remove former Premier Jason Kenney in 2022.

Kenney said separatism had traditionally remained a fringe movement, with independence parties typically securing only 1% or 2% of the vote. He said the COVID-19 pandemic mobilised activists angered by public health restrictions and government authority.

Separatist leader Jeff Rath said federal COVID-19 vaccine mandates pushed him towards supporting independence. Tanya Clemens, co-chair of the Let Alberta Decide group, said pandemic restrictions encouraged political organising.

The group's other co-chair, Keith Wilson, was a lead lawyer for the 2022 trucker convoy that paralysed downtown Ottawa for weeks in protest against vaccine mandates and other COVID-19 restrictions.

Energy policies at centre of Alberta's grievances

Wilson said Alberta's grievances extend beyond pandemic-era restrictions. With much of Canada's population concentrated in Ontario and Quebec, he argued that Liberal governments can win federal elections without significant support from Alberta, leaving the province vulnerable to policies opposed by its energy industry.

He cited Carney's proposed Pacific Link pipeline as an example of the problem, arguing that federal restrictions have discouraged private investment and could leave taxpayers financing the project.

Wilson said he opposed Alberta becoming part of the United States.

"I have no interest in substituting a master, that rules over my children's future, who's in Ottawa, with a new one who's in Washington," he said.

Other separatist leaders have sought contact with the Trump administration. Rath and fellow independence advocates have met US State Department officials in Washington three times to discuss Alberta's future.

Chief Sheldon Sunshine of Sturgeon Lake Cree Nation said Alberta could not leave Canada without the consent of First Nations, citing treaties that predate the province's creation. He said his nation would remain part of Canada even if Albertans voted for independence.

Sunshine condemned separatist leaders' meetings with US officials.

"It's absolutely treasonous to the people of Canada, people of Alberta," he said.

Separatists see gains regardless of vote outcome

Wilson said the referendum campaign had sparked unprecedented discussion about Alberta's place within Canada.

"I think we've already hit success when you look at the voter turnout," he said. "People are engaged and people are talking about this topic at a level that's unprecedented historically."

Rath said he would be thrilled if 30% of Albertans voted to begin the separation process, even if the proposal failed to secure a majority.

He wants Smith removed as United Conservative Party leader and said the party could split, potentially paving the way for a new pro-independence political party.

Separation debate may continue beyond Monday's vote

Some Albertans hope Monday's vote will end the debate rather than trigger a prolonged independence struggle similar to Quebec's.

Dave Malka, a 59-year-old Edmonton government employee who attended a pro-Canada rally on Sunday, criticised spending money on what he called a "referendum on a referendum" when the funds could instead be used for healthcare.

With Trump threatening Canada, Malka said the vote was coming at the wrong time.

"It seems to be happening at the absolute worst time when we should be united, instead we're fighting amongst ourselves," he said.

Malka expects voters to reject the proposal decisively but fears separatists will continue their campaign.

"This is only the start of separation Armageddon, if you will. This is their starting point," he said.

Jake Graham, 35, of Calgary, attended Carney's rallies wearing maple leaf-patterned pants and a Canada hockey jacket. He said he hoped a decisive outcome would settle the issue.

"I hope this squashes this for a long time to come and that it's clear and decisive, that these grumblings disappear for a while and we can be a united Canada," he said.