Premier Rachel Notley wasn't mincing words Wednesday after federal NDP leader Jagmeet Singh chastised the federal Liberal government for subsidizing the fossil fuel industry, and in particular, offering a financial backstop to Kinder Morgan's Trans Mountain pipeline expansion.

Singh said at a rally in Ottawa that he simply can't support the project and wants it scrapped as it places too much liability on Canadian taxpayers.

"There are talks of absorbing the risk of Kinder Morgan, which could put Canada, Canadians and the environment, to hold all the risk," he said.

"This would mean that the public would maintain all the risk, environmental and financial, to benefit private shareholders of a corporation in Texas. This is something that is not acceptable."

Finance Minister Bill Morneau has said the federal government is willing to compensate the pipeline's backers for any financial loss due to British Columbia's attempts to obstruct the expansion, which will triple the amount of crude oil the pipeline carries.

Singh has also taken to social media to say he thinks the expansion of the pipeline — running from northern Alberta to Burnaby — should not go ahead.

Liberals are giving Texas oil company <a href="https://twitter.com/hashtag/KinderMorgan?src=hash&ref_src=twsrc%5Etfw">#KinderMorgan</a> a blank cheque while dumping all the risks on Canadians<br><br>Rigged process, First Nations & local communities shut out, oil spill threats, science ignored & now billions on the line<br><br>It's clear this pipeline should not be built. —@theJagmeetSingh

Asked about the comments, Notley fired back on Wednesday.

"The private shareholders he's describing happen to be part of a company that will contribute … roughly $15 billion to the Canadian economy and will contribute to and support over 250,000 jobs in the country of Canada, so it is a ridiculously naive statement," she said.

Notley says Singh's opposition to the Trans Mountain pipeline expansion is premised on a lack of understanding of the economic stakes.

She says she's tried in the past to have that conversation but so far, the federal NDP leader has declined. She also questioned his maturity as a leader.

"We were disappointed we didn't have those conversations with him at that time and we still haven't," said Notley. "That's his choice, I hope at some point in the future he will take a more mature approach to his leadership."

(Scott Galley/CBC)

Notley also reminded Singh it's a mistake to continually pit the environment against the economy.

"To do that and forget the needs of working people, or to throw working people under the bus, means that both economic growth and environmental protection are bound to fail," said Notley.

Notley says she remains open to having a conversation with Singh about the merits of the project.

Singh says Notley is a good leader and that his criticism is aimed at Prime Minister Justin Trudeau and Ottawa's handling of the approval and regulatory processes.

Notley and B.C. NDP Premier John Horgan have sparred publicly over the project in recent weeks.

Alberta passed Bill 12, titled Preserving Canada's Economic Prosperity Act, which gives the Alberta government the ability to retaliate against B.C. over any delays to the expansion by driving up gas prices or restricting shipments of other energy products.

In response, the B.C. government filed a statement of claim in Alberta's Court of Queen's Bench over the legislation.

Notley also skipped the western premier's conference in Yellowknife this week to focus on negotiations. Deputy premier Sarah Hoffman represented Alberta at the meetings instead.