Federal NDP leader Jagmeet Singh says he doesn't anticipate losing seats in Saskatchewan, despite the expulsion of MP Erin Weir from his caucus.

"We're looking forward to having a strong campaign across Saskatchewan and particularly where we've held seats before, we're looking to regain and keep those seats," he told reporters in Saskatoon on Thursday.

Singh was in town to talk about issues like pharmacare and housing, and took the opportunity to announce Saskatoon-West riding MP Sheri Benson as the party's deputy leader.

He also took questions on Weir, saying he stood by the decision to expel the Regina-Lewvan MP from the party, following an investigation into allegations of harassment and sexual harassment.

"We made a decision to ensure safety in our staff and it was supported by caucus. And that decision was final," he said.

On Tuesday, Weir announced he would not be running again, with a new NDP candidate for the riding yet to be nominated.

Éric Grenier, a CBC poll analyst, expressed doubt on Singh's assertion NDP would win back its Regina-Lewvan seat.

He pointed out Weir only won his seat by 132 votes in 2015, and said NDP fortunes across Canada, and Saskatchewan, have gone downward since then.

"If Erin Weir had been the NDP candidate for the NDP, he still would have a big challenge on his hands to win that seat. Without an incumbent candidate, I think it makes it all the harder for the New Democrats to win," he said, adding this will further be the case if the riding organization is divided on the party's move to expel their former candidate.

The NDP currently hold two seats, with Benson's Saskatoon riding and MP Georgina Jolibois' seat in the Desnethé-Missinippi-Churchill River riding.

Across the country, Grenier points to the growing numbers of Conservative premiers elected as a way to drive opposition to the Liberals' policies, such as carbon pricing.

"It's putting on the agenda some issues that are already a little problematic for the Liberals and ones that work out pretty well for the Conservatives," he said.

At this point, it looks likely long-time MP Ralph Goodale will hold onto his Regina-Wascana seat, but that will likely be the only seat the Liberals win in Saskatchewan, according to Grenier.

And while the Greens have made strides and recently won a byelection in the British Columbia riding of Nanaimo-Ladysmith, with the party still polling in the low to mid single digits in Saskatchewan, it's unlikely it will be able to make much of a dent in the province in the October 2019 election, said Grenier.