"But I think that overall, the idea of adding the value in Canada of developing, upgrading, processing, refining, our own natural resources is a good one," Mulcair said in an interview.
Postmedia News reported Monday that Mulcair's comment followed up on a proposal from publisher David Black to build a refinery near the British Columbia coastal town of Kitimat, which would be the terminus of the Northern Gateway pipeline, if that is ever built.
The refinery near Kitimat would have a price tag of $13 billion. The benefits would include increasing Canada's energy independence.
The pipeline, which would be developed by Canadian oil giant Enbridge, would start at Bruderheim, Alberta, and end at Kitimat in northern British Columbia.
On the other hand, Mulcair said the Northern Gateway pipeline "goes through some of our most pristine ecosystems."
"It's extremely dangerous on that coast and I just don't think it makes any sense," to construct the pipeline, he said.