The federal NDP and Liberal leaders visited the Manitoba riding of Brandon-Souris again on Wednesday, as voters there prepare to elect a new MP at the end of the month.

A byelection will be held Nov. 25 in Brandon-Souris, a riding that has voted Conservative in every election but one since its inception.

But given the Senate expense scandal brewing in Ottawa in recent weeks, the New Democrats and the Liberals are hoping to change the riding's colour.

"We know that it's a Conservative riding, but you know what? We also realize that it's more of a three-way race than it's been in the past," NDP Leader Tom Mulcair told reporters on Wednesday, during his second visit to the Brandon area.

"We're hopeful that people are looking at this as not something the Conservatives can take for granted," said Liberal Leader Justin Trudeau, who marked his fourth visit to the riding.

The byelection is being held to replace former Conservative MP Merv Tweed, who resigned in August to take a top job at rail company OmniTrax.

The Liberal candidate in Brandon Souris is Rolf Dinsdale, whose father, Walter Dinsdale, was the area's Progressive Conservative member of Parliament for 32 years.

Running under the NDP banner is Cory Szczepanski, a welder and a former president of the Brandon District Labour Council.

Representing the Conservatives is former Manitoba MLA Larry Maguire, who says recent poll numbers — which put the Tories behind the Liberals — do not faze him.

"The only one that counts is Nov. 25," Maguire said, adding that voters he's spoken to weren't focusing on the Conservatives' Senate troubles.

"The issues that we're hearing at the door are infrastructure, the new CETA agreement," he said, referring to a tentative free trade deal Canada signed with the European Union last month.

"This constituency depends on exports of grain, oil and livestock."

While many voters said they won't break with generations of voting tradition, some said change could potentially be on the way in Brandon-Souris.