Ahead of the fall sitting of Parliament, NDP Leader Tom Mulcair is looking to brand Prime Minister Justin Trudeau as the fresh face of Stephen Harper's old policies.

"We're facing a Liberal government that has no plan to reduce greenhouse gases in Canada, that is exporting the weapons of war to a very repressive Saudi regime and that hasn't brought about a single change to Bill C-51," he said, referring to the anti-terrorism bill enacted after the attack on Parliament Hill.

"We've got a lot of questions for the Trudeau government on their failures to deliver on promises and the fact that they are continuing a lot of Stephen Harper's policies."

Mulcair, who is facing calls for his resignation from some inside his parliamentary caucus, said the Liberal government has done virtually nothing on the environment file and is sticking with Harper's greenhouse gas targets.

Tom Mulcair wants to make something clear: despite the rumours, he plans to stay on as leader of the NDP until his permanent replacement is chosen. He joins us to talk about his future... and that of his party. 14:15

"We've got a government, now, that has changed tone, and I'm happy with it, but they haven't changed the plan. It's still Harper's plan. They haven't changed the timelines, it's still Harper's timelines. They haven't done anything, Canada is still mired," Mulcair said in an interview with Chris Hall on CBC Radio's The House.

Environment Minister Catherine McKenna has said, however, that Harper's targets will be "a floor not a ceiling," and she is pushing hard for a national price on carbon to help the country meet the targets it committed to during the Paris climate talks last fall.

"What is really clear … is that every jurisdiction needs to have a price on carbon, and the premiers have all recognized that a price on carbon is part of the solution [to fight climate change]," Catherine McKenna said in an interview with CBC Radio's The House earlier this year.

So far, both Saskatchewan and Nova Scotia have signalled they will not support the unilateral imposition of a carbon price, which could stymie a national consensus.

Mulcair also pointed to Liberal inaction on health care, and the silence in the spring budget on a new funding escalator.

"Canadians will know that Mr. Trudeau simply failed to deliver, they'll know that he's maintaining Stephen Harper's cuts to health care, and he's not putting that money back, contrary to promises he made," he said.

Health Minister Jane Philpott will meet with her provincial and territorial counterparts in the fall in an effort to hash out a new health accord, which will include new funding commitments.

"I am as anxious, or more, as you are to get this done, and I think Canadians are going to be pleased," Philpott told CBC News in April. "I would like to see the [discussions] wrapped up toward the end of this year and hopefully have a big announcement in 2017."

Mulcair's leadership questioned

Mulcair was adamant he will stay on as leader of the party until his successor is chosen by party members next year, despite criticisms of his leadership by some over the summer.

"You bet," he said when asked if he'll be fronting the party in the House of Commons. "Last spring, in the wake of what happened in Edmonton, I sat down with caucus, I listened to everyone, and there was a really good discussion, and at the end of that I was asked to stay on until the next leader is chosen. I am looking forward to being a steady hand on the tiller as we bring the ship into port for the next leader."

Party members at the party's convention in April voted 52 per cent in favour of holding a leadership contest to replace Mulcair.

He said he was not aware of any caucus members who were looking to push him out of power ahead of the next leadership race.

"The people that I've spoken to, throughout the summer, have only expressed support to me. The members of the caucus with whom I spoke to, and frankly I spoke with almost all of them, and it's going very well."

The Montreal-area MP said he also has the support of the party's president, Marit Stiles, who was elected at the party's convention in Edmonton.

"Marit Stiles and I get along extraordinarily well, and I spoke to her a number of times during the summer. She has my support and I certainly expect to have hers as well. I hope that I do."

He said he has a strong team in the House, and a front bench full of talented MPs — many of whom he expects will throw their hats in the ring to run for the permanent leadership — who are ready to take on the Liberals and shed light on their shortcomings.

"I think the party is very effective in the House," Mulcair said. "As an opposition party, that's where we really got a chance to show our stuff. We have a tradition of doing that, we did it well with Mr. Harper. As the shine starts to wear off a little bit over the course of the fall, we'll be able to take some of those substantial battles forward with the Liberals."