Prime Minister Justin Trudeau says conservative premiers are playing games with national unity by threatening the country's future if they don't get their way on an environmental-assessment bill.
The six premiers said in a letter to Trudeau Monday that he must accept every one of the amendments the Senate has made to Bill C-69.
The Senate made 187 amendments to the bill, which overhauls how Canada assesses major national energy and transportation projects for their environmental, economic and health impacts.
Conservative deputy leader Lisa Raitt says the prime minister has a duty to listen to the five provincial and one territorial premiers' demands because they represent a majority of the Canadian population.
Trudeau says his government will accept some amendments that improve the bill but will not all of them, including one that he says makes it optional to consult Indigenous communities.
He also says he rejects any suggestion that national unity is under threat just because conservative premiers aren't getting what they want.