Alberta Premier Jason Kenney is warning Prime Minister Justin Trudeau of potential “devastating” consequences for the Canadian economy and global markets if Teck Resources Ltd.’s Frontier oil sands proposal is rejected.

“It is with great urgency and deep concern that I am taking the unusual step of writing to you about the Teck Frontier project, and urge you and your cabinet colleagues to ensure its timely approval this month,” Kenney wrote in a letter that was addressed to Trudeau last week and shared on the premier’s Twitter account late Monday.

The $20.6-billion proposed oil sands mine, which would be located 110 kilometers north of Fort McMurray, Alta., is pending approval from the federal cabinet, which has until the end of this month to make a decision.  

Kenney argued there is no reason to justify denying the project.

“Given the level of economic benefits, Teck’s environmental commitments, and broad Indigenous support for Frontier, if this project is not approved, it would send a chilling signal regarding federal intentions on future oil sands or natural resource development projects,” Kenney wrote.

“As you know, investment capital, and especially foreign investment, is looking for signs of hope from our governments. A decision to kill the project at this late hour, after all that Teck has done to satisfy regulators and social environmental concerns, would echo in global markets like a slamming door.”  

Kenney also warned the rejection of the project could bring Western alienation to a “boiling point.”

Speaking in Calgary Monday, Finance Minister Bill Morneau said the government has not yet made a decision on the project as climate concerns weigh. Teck said early last week is has a goal of becoming carbon neutral by 2050.