Christine Melnick says she doesn't want to cause a stir that would detract from party business.
Melnick was removed from the government caucus Tuesday, after going public with accusations Premier Greg Selinger's office had made her a scapegoat for an immigration controversy.
Selinger has denied the accusation, and said Melnick was ousted because she failed to take responsibility for the issue.
The NDP convention comes at a time when the party's popularity has dropped sharply, according to opinion polls.
Melnick will sit as an Independent and says she plans to run for re-election in 2016.
When Melnick was the province's immigration minister in 2012, she introduced a resolution in the legislature criticizing the federal government’s plan to take over some immigration programs run by the province.
The previous day, her assistant deputy minister Ben Rempel and other bureaucrats issued an email to government-funded immigrant service agencies telling them of the event and saying that staff should feel free to come — even if it meant taking the afternoon off. More than 400 people packed the public gallery and an overflow room.
Melnick initially denied being behind the invitations, but the provincial ombudsman said she in fact was.