The vote is in The Pas, a seat vacated last May when New Democrat Frank Whitehead resigned for health reasons.
The Pas has generally been considered a safe seat for the NDP government — Whitehead won 73 per cent of the vote in the last provincial election.
But the NDP's popularity has sunk in opinion polls since the government raised the provincial sales tax in 2013.
Running this time for the NDP is Amanda Lathlin, a former band councillor and daughter of Oscar Lathlin, who represented The Pas between 1990 and 2008.
The Progressive Conservatives are putting up Jacob Nasekapow, a former band councillor in Moose Lake, while the Liberals have nominated Inez Vystrcil-Spence (VISS'-terr-sill), who has worked as a health director for the group that represents all northern Manitoba First Nations.
The byelection means Premier Greg Selinger and his government will be keeping a low profile for the next few weeks.
Under provincial law, the government is not allowed to announce new programs or make new promises, except for matters of public safety.