On the first working day of Dominic LeBlanc's new portfolio as minister of intergovernmental and northern affairs and internal trade, a joint announcement from two premiers on Thursday appears to be emblematic of Ottawa's deteriorating relationship with the federation.

Premier Doug Ford and Saskatchewan Premier Scott Moe stood side by side in Saint Andrews to announce Ontario will support the Prairie province in challenging the federal government's right to impose a carbon tax on provinces that don't comply with its climate change plan.

Ontario Premier Doug Ford, left, and Saskatchewan Premier Scott Moe talk with reporters during a meeting in Saint Andrews on Thursday. Ford and Moe have agreed to fight the imposition of a carbon tax. (Andrew Vaughan/Canadian Press)

It's one of several challenges LeBlanc will be responsible for managing in his new post, and it's why the veteran politician got the job during Wednesday's cabinet shuffle, according to University of New Brunswick political science professor J.P. Lewis.

"We're peaking in terms of regional and, more specifically, provincial challenges that the prime minister and the government are facing," Lewis said.

Changing domestic landscape

The Canadian political landscape is changing with the arrival of new premiers. In the most recent instance, Ford presents an opposing view to the Trudeau Liberals' key policies, especially carbon tax and climate policy.

Another premier could join the fold from the right before the 2019 federal election if United Conservative Party Leader Jason Kenney wins the upcoming Alberta election.

Elections will be held in Quebec and LeBlanc's home province of New Brunswick this fall.

In light of the current circumstances in the federation, it would be a promotion. - J.P. Lewis, political scientist

And it's not just federal-provincial relationships that are becoming fraught, as Lewis noted.

LeBlanc is charged with handling interprovincial disputes — Alberta and British Columbia, for instance — on items such as pipelines and cross-border trade.

"We may see the type of contentious relationships that we haven't seen in, really, between the provincial and federal governments in a while," Lewis said.

Promotion for LeBlanc

He said the prime minister, with an eye on the 2019 election, appointed a political veteran and close confidant to handle an important portfolio since the voters' evaluation of how Justin Trudeau leads the federation is significant.

"In light of the current circumstances in the federation, it would be a promotion," Lewis said of LeBlanc's new role.

Lewis said it falls under a pattern of previous prime ministers to appoint stronger ministers, or "political fixers," to key portfolios or problem areas. He said Stephen Harper used the late Jim Prentice in this fashion.

Dominic LeBlanc was sworn in as minister of intergovernmental and northern affairs and internal trade on Wednesday by Michael Wernick, clerk of the Privy Council, during a ceremony at Rideau Hall. (Justin Tang/Canadian Press)

Gabriel Arsenault, assistant professor of political science at the University of Moncton, echoed Lewis in saying it's a promotion.

"It is an increasingly important department, because we see that there is a lot of acrimony between the provincial governments and the federal government," Arsenault, speaking in French, told Radio-Canada.

Trans Mountain Pipeline

He said the number one issue on LeBlanc's list is the federal government's purchase of the Trans Mountain Pipeline, which lies at the centre of the Alberta-British Columbia tensions.

The federal government stirred up tensions when it decided to take over the Trans Mountain Pipeline expansion, which will bring a significant increase in tanker traffic off the B.C. coast. (CBC News)

Number two on that list: Ford's push to get Ontario out of the carbon market.

Following Wednesday's shuffle, LeBlanc said the federal and provincial governments share a common interest in strengthening the economy and creating more jobs.

"There'll be a lot more, I think, that we have in common than we may disagree on, and my job will be to work with all of these leaders in a way that advances the interests of Canadians," he said.

On Thursday, the Beauséjour MP tweeted out a commitment to hold a premiers meeting on trade and that "removing trade barriers between Provinces and Territories is vital to growing our economy."