Embattled Canadian leader Justin Trudeau came under fire for the development of a controversial oil pipeline in the final election TV debate dominated by environmental issues.
Mr Trudeau, 47, was on the defensive over the approval of a pipeline expansion project to help carry oil from the tar sands of Alberta in the north to ports in Vancouver for export abroad.
"We have to stop these pipelines and fracking all across Canada," said the head of the Greens, Elizabeth May. "The young Swedish activist Greta Thunberg is right: our house is burning, how dare you?"
Mr Trudeau has said profits from the pipeline will be reinvested in the environment. But the project has also been criticised for not consulting indigenous groups.
His popularity has slumped in the wake of a blackface scandal and allegations he pressured his attorney-general to abandon a criminal prosecution of Quebec engineering firm SNC-Lavalin, handing Conservative leader Andrew Scheera five-point poll lead ahead of the October 21 election.
During a 2016 visit, Mr Trudeau drew mockery by donning traditional Indian robes.
As Mr Trudeau accused his rival of planning to cut services for Canadians and caving in to big polluters, the Liberal Party released a photoshopped image of Mr Scheer, 40, wearing a red “Make Pollution Free Again” cap, resembling those worn by supporters of US President Donald Trump.
The spirited debate in French was watched primarily in Quebec, a key battleground where Mr Scheer – who is less comfortable speaking French – and Mr Trudeau have been on the hunt for votes.
“This has been a Quebec-centric election in certain ways,” said Jim Farney, professor of politics at the University of Regina.
Mr Trudeau, 47, was also forced onto the defensive over his handling of the SNC-Lavalin affair and his treatment of Canada’s indigenous communities, 56 of whom still lack access to clean water.
But it was the climate that kept coming up, in particular Mr Trudeau’s purchase of a contentious oil pipeline.
According to an Ipsos poll, climate change is the second most important issue to voters, after healthcare, in this election.