The federal government isn't expecting Sunday's meeting between Prime Minister Justin Trudeau and the premiers of Alberta and British Columbia to lead to an agreement to get the stalled Trans Mountain pipeline expansion project moving again.

A senior federal official told CBC News there is almost no chance that B.C. Premier John Horgan will drop his opposition to the project on environmental grounds.

'There's a carrot and stick approach...there's been a lot of carrots from the federal government to B.C.,' says the Alberta premier. 7:41

Instead, the official said, Trudeau will use the meeting to explain the steps he intends to take to ensure the pipeline expansion gets built. The official would not elaborate on what those steps might be.

The official said Trudeau and Horgan have been discussing a possible compromise on the pipeline for months. The prime minister put the prospect of more money for coastline protection on the table, and even promised to "take the heat" for approving the project, the official said.

The idea was that Horgan would be able to extract concessions from Ottawa to address his environmental concerns — while still expressing his opposition to the project publicly and deflecting his supporters' political anger at the prime minister.

Inflated expectations for Sunday's meeting

But those talks clearly failed; Horgan is standing firm on the issue, despite the fact the federal government holds constitutional authority over the pipeline.

This dynamic clearly frustrates Alberta Premier Rachel Notley. A senior Alberta government source cautioned that the expectations attached to Sunday's meeting are too high and are "going to keep growing."

The Alberta official suggested the prime minister likely called this meeting — and decided to abruptly return to Canada in the middle of a multi-country foreign trip — because of the criticism he took for travelling in the middle of what Notley has described as a nascent constitutional crisis.

The Alberta official said the Notley government doesn't expect "anything concrete" or "new" to come out of the meeting — at least from Alberta's perspective.

Notley met Wednesday with federal Finance Minister Bill Morneau for what the Alberta official described as a "very positive" discussion. The Alberta official said Morneau sent very positive signals about the possibility of a federal investment to move the project along.

Natural Resources Minister Jim Carr: 'We're prepared to look at all reasonable options.' (Justin Tang/Canadian Press)

Those private assurances align with Natural Resources Minister Jim Carr's recent statement that Ottawa is prepared to consider assuming some of the project's financial risks as a solution to the Trans Mountain pipeline expansion feud.

"I think that we're prepared to look at all reasonable options," Carr told CBC Radio's The House on Friday.

"The government of Canada is saying, 'We'll look at de-risking the project so there's more certainty.'"

Prime Minister Trudeau and his ministers have vowed for months that the pipeline expansion would be built. An emergency cabinet meeting was held earlier this week to discuss the impasse; ministers emerged offering no clear indications of a path forward.

MPs look ahead to pipeline meeting between PM, premiers 10:16

Providing a guarantee that Ottawa would cover for some potential losses could be one of the options on the table, according to Carr.

Earlier this week, the minister said that a federal investment in the Trans Mountain pipeline was also possible.

Those two ideas are only options under consideration at this point, along with other legal and regulatory manoeuvres.

Carr said investor confidence is key to Canada's economy, and channels need to remain open to U.S. and Asian markets.

"Delay means cost and cost means uncertainty."

Agreement still far off

The opposition from the B.C. government has been focused on protecting the coast and looking at the potential environmental impacts of the project.

Carr cited as a preventative measure the federal government's new Oceans Protection Plan, which earmarks $1.5 billion for defending Canada's ocean coastlines to protect killer whales, guard against oil spills and enable trade.

But Premier Horgan has remained immovable — despite the fact that the federal government holds ultimate constitutional authority over the pipeline.

"There are those out there who are, at this point, calling this moment we are in a constitutional crisis for the country," Notley said. "And I don't know really if that's too far off."

She has also said her province is willing to shoulder some or all of the financial risk, and is considering investing in the pipeline project. She said the federal government should think about doing the same.

"With good will and a genuine search for common ground, I guess we should be somewhat hopeful something good will happen, but it depends on how entrenched and how dug in people are and to what extent they're prepared to move," Carr said.

Prime Minister Justin Trudeau, right, with British Columbia Premier John Horgan. The premier can't support the Trans Mountain project without courting a political backlash from his political allies in the Green Party. (Darryl Dyck/Canadian Press)

A compromise could be reached Sunday but universal satisfaction seems unlikely.

The results of the meeting could face staunch opposition from the B.C. Green Party, which supported Horgan on his road to the premiership.

Andrew Weaver, B.C.'s Green Party leader, told The House that if Horgan agrees to a compromise that allows the pipeline to go ahead, he'll fight that decision.

"We can never support any measures or any government that would allow diluted bitumen to flow in our coastal waters. Period," he said.

"Everyone has a line in the sand. Diluted bitumen is ours."