Once secured tightly to Canada’s economic engine, the carbon tax now flaps dangerously in the wind: the critical strap that is the NDP has come loose.

On Thursday, Jagmeet Singh hinted that he will oppose the country’s current carbon pricing regime, vaguely stating that “big polluters” must pay their share, and remaining mute on the subject of the consumer carbon price. It was an echo of a speech Singh made in April at the Broadbent Institute’s annual conference, in which he accused both the prime minister and the Conservative leader are failing on climate.