The NDP is caving to political pressure from Conservative Leader Pierre Poilievre when it comes to its stance on the consumer carbon price, Prime Minister Justin Trudeau said on Friday.

Speaking to reporters in Ste-Anne-de-Bellevue, Que., Trudeau blasted the NDP on its equivocation on the consumer carbon price while responding to a question about the upcoming byelection in Montreal.

鈥淚 do believe that Jagmeet Singh and the NDP actually do care about the environment. It鈥檚 just increasingly obvious that they have no idea what to do to fight against climate change,鈥� Trudeau said.

鈥淭hey had no ideas on the environment, and one of the first things they do after walking away from that agreement to deliver progressive things for Canadians, is walk away from any plan to fight climate change.鈥�

Trudeau was referring to the NDP leader鈥檚 announcement last week that the party was leaving the supply-and-confidence deal with the minority government.

On Thursday, Singh said the NDP is working on a plan that wouldn鈥檛 put the burden of fighting climate change on the backs of workers, but wouldn鈥檛 say if that plan would include a consumer carbon price.

Singh鈥檚 noncommittal position comes as the NDP tries to frame itself as a credible alternative to the Conservatives in the next federal election.

While the Conservatives have blamed the carbon levy for raising the cost of living, the prime minister once again cited the parliamentary budget officer鈥檚 finding that eight out of 10 households in jurisdictions that have the federal backstop receive more money in rebates than they pay in carbon pricing.

鈥淎nd yet, Jagmeet Singh and the NDP are caving to the political pressures from Pierre Poilievre and from the Conservatives,鈥� Trudeau said.

鈥淭hat鈥檚 not what Montrealers expect and deserve.鈥�

Voters will be heading to the polls on Sept. 16 in Montreal鈥檚 LaSalle鈥斆塵ard鈥擵erdun. The seat was held by former justice minister David Lametti before he resigned.

Another byelection will be held on the same day in the Winnipeg riding of Elmwood鈥擳ranscona, a seat that has been held by the NDP.

Poilievre responded to Singh鈥檚 Thursday comments by releasing a video pointing out that the NDP has voted time and again in favour of the Liberals鈥� carbon price.

British Columbia Premier David Eby also changed his tune on Thursday, promising that a re-elected NDP government would scrap the long-standing carbon tax and shift the burden to 鈥渂ig polluters,鈥� if the federal government dropped its requirements.

Economists are widely in favour of carbon pricing, arguing it is the most cost effective way to reduce emissions.