Alberta Premier Danielle Smith and Ontario Premier Doug Ford are proposing a new oil pipeline that would stretch from Western to Central Canada — a concept that parallels the cancelled Energy East project.

The 500,000 barrel a day pipeline would connect crude oil production in the prairies with domestic refineries in Ontario.

“Pipelines have gone from impossible to a national imperative,” Smith said at a news conference.

“The Alberta oilsands have gone from a target to a national treasure, and we’re launching the greatest expansion of oil and gas infrastructure and production in decades.”

The proposal comes just days after Smith and Prime Minister Mark Carney announced details of a proposed West Coast pipeline. It would move a million barrels of Alberta oil per day along a new line that would follow a similar path as Trans Mountain, before ending at a shipping terminal in Delta, B.C.

The Alberta-to-Ontario line, called Northern Shield, is a 3,300-kilometre proposed pathway that would stretch from Hardisty, Alta. to Sarnia, Ont. It would run through Regina and Winnipeg before looping around the Great Lakes near Toronto.

John Jeffrey, chief executive of Saturn Oil & Gas Inc., said the industry could see a major switch from having too much oil and not enough shipping capacity in the late 2010s, to potentially having too many options.

Jeffrey said he isn’t sure Saturn and other producers would have enough crude to fill those pipelines even if plans work out.

“I don’t see the demand for this line,” said Jeffrey. “I don’t think there’s enough supply even coming online in the next 10 years to fill all this.”

Northern Shield would move an estimated 500,000 barrels of oil per day, with room to expand to 800,000 — feeding Ontario refineries and providing redundancy to existing infrastructure, according to Ford.

Ontario is conducting a cost estimate that will be ready by the end of the year, he said.

“Folks, we are an economic powerhouse around the world, and now we have to unleash that powerhouse,” Ford said in Calgary.

The proposal has some similarities with Energy East, a project originally championed by TransCanada Corp., now TC Energy Corp.

The $15.7-billion pipeline would have run from Alberta to Irving Oil Ltd.’s refinery in Saint John, N.B. But TransCanada cancelled the project after facing a series of setbacks, including opposition in Quebec and a regulatory decision to consider both the project’s upstream and downstream emissions.

The factors that supported Energy East are no longer in place, said Andrew Leach, a professor in economics and law at the University of Alberta. It was a “last resort” project to get a pipeline built while oil prices were rapidly increasing at a time of huge investment in production.

“None of those circumstances are on the table,” said Leach.

While oil and gas companies were the proponents pushing for new pipelines more than a decade ago, governments are now largely in the driver’s seat, advocating for projects that appear to mirror cancelled proposals.

Smith had originally pitched her West Coast pipeline would end in northwestern British Columbia — similar to Enbridge Inc.’s ill-fated Northern Gateway — though the proposed project would now end on the southern coast.

And South Bow Corp . has proposed a new line into the United States using parts of its cancelled Keystone XL pipeline project, which had cross-border permits cancelled by two different presidents.

“Look at how Canada’s public opinion has changed. It’s done a 180 on energy,” said Smith.

Jeremy McCrea, an energy analyst at the Bank of Montreal, argues that over the past decade, every new pipeline proposal has been met with a lot of skepticism, red tape and regulation.

McCrae raised doubts all of the proposed lines would materialize.

“More projects that are starting should give investors more optimism that one of these will go through to the finish line here,” he said.

Northern Shield would connect to refineries in Sarnia, but Leach, an expert in oil and gas policy, said that there are limitations on much more oil can be shipped out of the Ontario hub.

“There’s no refineries in Sarnia that are sitting there saying we’d love more oil but we can’t get it,” said Leach.

Smith added that the corridor could “eventually” reach the Atlantic Ocean for exports to Europe, but didn’t provide details on which pathway it may take.

Jackie Forrest, executive director of the ARC Energy Research Institute, said that Northern Shield has a lower likelihood of materializing compared to the West Coast line announced just days before.

A feasibility study on the west-east corridor will be “critical” to weigh the cost of construction against the cost for producers to fill it after it’s built, which she expects will be high.

“The question is what is the price for energy security?” Forrest said. “And how much are people willing to pay?”

Given the line from Alberta to B.C. revealed last week could cost up to $43 billion, one economist predicted the line to Ontario — a much greater distance — could double that price tag.

“We’re probably considering double that cost,” said Charles St-Arnaud, chief economist with Servus Credit Union in Alberta. “That’s a lot of capital to be committed up front.”

Leach points out that Enbridge has its own line running from Hardisty through the U.S. and the Great Lakes to Sarnia.

“Who’s going to pay for having redundant infrastructure to Sarnia?”

Smith and Ford said they are now seeking support from Saskatchewan and Manitoba, while they work to get 77 Indigenous communities onside.

Moshe Lander, a senior lecturer in economics at Concordia University in Montreal, said there may not be an appetite among industry to build more pipelines.

“Private companies aren’t stepping forward and saying we need pipelines or we’re willing to put our money into pipelines, even after the memorandum of understanding from months ago,” Lander said. “Nobody came forward.”