CALGARY -- Alberta Premier Jason Kenney took what he says is the "unusual step" of writing directly to Prime Minister Justin Trudeau to stress the importance of obtaining federal approval for the proposed Teck Frontier mine.

The massive $20 billion oilsands project is proposed to be built in northern Alberta and would be capable of producing more than 250,000 barrels of oil every day. The federal government has until the end of February to decide whether or not to approve the project.

“If this project is not approved it would send a chilling signal regarding federal intentions on all future oilsands or natural resource development projects,” Kenney’s letter to Trudeau said.

The premier posted the four-page letter, dated Feb. 5, to social media on Monday.

Kenney also said Teck has done its part to meet or exceed all regulatory requirements for the proposed project.

"Alberta stands willing to work with Ottawa on climate policy," the letter said.

Keith Stewart, a senior energy strategist with Greenpeace Canada, questions the urgency for the approval of the project.

"The Teck mine proposal would just join the 20 other oil sands projects sitting on the shelf because they don’t make economic sense in a world moving away from oil," he said last week.

"The rest of Canada needs to support the workers and communities currently dependent on oil through the necessary transition to a zero-carbon economy, rather than offer the false hope of an oil boom that never ends."

Federal Finance Minister Bill Morneau, who spoke to a crowd of business professionals in Calgary on Monday, said Ottawa has gone through a "rigorous process" in determining the future of the project.

"We are going through a process, which has been a robust process, that will culminate in the cabinet decision on the project," said Morneau.

"We’ve not yet come to a decision yet, it hasn’t yet come to cabinet formally."

In his letter, Kenney said rejecting the project would be "devastating."

"Here in Alberta, it would be interpreted as a rejection of our most important industry and could raise roiling Western alienation to a boiling point – something I know your government has been attentive to since the election," Kenney said.