Province, feds submit closing arguments in Ontario carbon tax court battle

Ontario’s constitutional challenge to Ottawa’s imposition of a carbon charge was left in the hands of five Appeal Court justices on Thursday after the hearing wrapped up with each side pressing the court to find in its favour.

In closing submissions, a federal lawyer warned that climate change posed an urgent threat. Ottawa, she said, has addressed an issue of national concern in a manner that respects provincial jurisdiction.

Ontario, however, stood by its view that the Greenhouse Gas Pollution Pricing Act — if deemed constitutional — would undermine co-operative federalism by allowing Ottawa to overstep the dividing line between federal and provincial spheres of authority.