(CP)-Alberta Premier Danielle Smith is threatening another legal challenge against Ottawa’s environmental assessment law, a move federal Environment Minister Steven Guilbeault is dismissing as a political stunt. The federal Impact Assessment Act was enacted in 2019, but a Supreme Court of Canada ruling last year found much of it unconstitutional. In response, Prime Minister Justin Trudeau’s Liberal government made changes to the bill in the summer. But Smith said in a Thursday letter to Trudeau that the changes aren’t good enough. Smith said the province would mount a legal challenge in four weeks if Ottawa doesn’t commit to further changes. “The federal government continues to play politics and cater to activists,” she said in a Friday news release, accusing the Liberals of failing to meaningfully consult with Alberta. Smith’s ultimatum…