Voters in the federal ridings of Provencher and Brandon-Souris are headed to the polls November 25. Prime Minister Stephen Harper announced the byelections today.

The Provencher seat opened up when former public safety minister Vic Toews resigned in July. Brandon-Souris became open after Conservative MP Merv Tweed left to become president of the shipping company Omnitrax.

The Conservatives are widely expected to hold those ridings. However, controversy over alleged party interference in the choice of a candidate for Brandon-Souris has angered local Conservatives and given opposition parties some hope for an upset.

Other ridings holding byelections include Bourassa (Quebec), and Toronto Centre (Ontario). Those two ridings are shaping up as an epic battle for opposition supremacy between the Liberals and the NDP.

Both are longstanding Liberal strongholds, left vacant after the resignations of former interim Liberal leader Bob Rae and veteran MP Denis Coderre.

- With files from Canadian Press