Premier Bob McLeod is demanding a rollback of natural resource regulation pending legislation, claiming it threatens national unity in a joint letter with five conservative premiers sent to Prime Minister Justin Trudeau.

A pair of federal bills, C-69  and C-48,  will risk Canada's economic well-being and national unity if left untouched, according to McLeod and his counterparts from Ontario, New Brunswick, Manitoba, Saskatchewan, and Alberta.

Trudeau said the premiers' position of "threatening national unity if they do not get their way is completely irresponsible."

Bill C-69 revamps federal rules on major national resource projects, and would affect government evaluation of pipelines and inter-provincial highways. Last week, the senate proposed 187 amendments to the bill, which Ottawa mostly rejected.

In their letter, the premiers said the bill would make resource projects "virtually impossible" and deprive the economy of investment. It also "upsets the balance struck by the
constitutional division of powers by ignoring the exclusive provincial powers over projects
relating to these resources," they wrote.

"The federal government must recognize the exclusive role provinces and territories have over the management of our non-renewable natural resource development or risk creating a constitutional crisis," the letter says.

The bill should be rejected, they wrote, unless the senate's amendments were included.

Bill C-48 formalizes an already observed practice of prohibiting oil tankers off the north coast of British Columbia.  The bill wouldn't stop tankers from accessing the Trans Mountain Pipeline in Burnaby on the south B.C. coast, but it would block pipelines to deepwater ports that allow larger vessels further north.

The Senate Committee on Transport and Communications recommended scrapping it, but a full senate vote scuttled the idea, clearing the way for its third reading and assent from the Governor General.

The premiers claim the bill discriminates against western Canadian crude products, in addition to threatening the economy and national unity.

"We would urge the government to stop pressing for the passage of this bill which will have detrimental effects on national unity and for the Canadian economy as a whole," they wrote.

Frame Lake MLA Kevin O'Reilly said Premier McLeod failed to consult other MLAs before signing the letter, showing colonial disregard.

"There was no consultation or even notice provided to regular MLAs, the same colonial approach that he has pinned on the federal government," he wrote on social media. "I would be curious to know whether there was any notice given to Premier McLeod's cabinet colleagues."