WINNIPEG -- Former Manitoba health minister Theresa Oswald has laid out her ground game for her bid to topple her own party leader and premier.

Oswald told several dozen supporters at her leadership campaign launch on Sunday that the NDP cannot win re-election with Greg Selinger at the helm. She also said the next election cannot be given to a Progressive Conservative party she accused of being "anti-gay, anti-women."

Oswald pointed to Tory Leader Brian Pallister's voting record, including his opposition to same-sex marriage a decade ago in Parliament. Pallister also last year opposed a new Manitoba law that requires schools to accommodate gay student support groups.

Oswald also pointed to the recent Tory nomination of James Teitsma, who until recently was a board member of the Association for Reformed Political Action. The group aims to bring Reformed Christian beliefs into politics and opposes abortion and same-sex marriage. Teitsma will carry the Tory banner in the Radisson constituency in east Winnipeg.

"These are the true colours (of the Tories), people," Oswald said.

"We cannot have someone with their hands at the wheel who only wants to govern for the privileged few and not for all Manitobans. Its a real risk."

Oswald and four other former cabinet ministers who resigned from their portfolios in November have put Manitoba's governing New Democrats in an unusual spot. They challenged Selinger's leadership as the NDP continued to slump in opinion polls, and went public with the party's inner turmoil.

Selinger, who has led the NDP since 2009, has vowed to stay on as premier and fight to keep his job at a party convention March 8.

Oswald has been receiving more support in recent days, although it is far from clear whether she will have enough to topple Selinger.

The four other ministers who resigned in November were at her campaign launch, as were several government staffers including a former top Selinger adviser, Anna Rothney. Also on hand were Nancy Allan, a former education minister who was demoted from cabinet in 2013, and Ron Lemieux a long-time minister who currently holds the Culture and Tourism portfolio.

Lemieux will continue to serve in Selinger's cabinet while publicly backing the woman trying to oust the premier. Lemieux said he and others have received assurance from Selinger that they will not face retribution.

"When Greg says he is going to allow everyone and anyone to make their mind up as to who they believe can lead us to victory in the next provincial election ... I take him on his word," Lemieux said.

There are no other candidates in the race so far. Selinger has said he will file his nomination papers before the Jan. 6 deadline. Infrastructure Minister Steve Ashton, who ran against Selinger in the 2009 leadership race, is widely expected to throw his hat in the ring once again.

Polls have suggested the NDP could lose the bulk of their seats and be reduced to a rump party after 15 years in power. The next election is slated for April, 2016, and Oswald said Sunday she and the other rebel cabinet ministers tried to keep the NDP dissent behind closed doors.

"We did everything in our power to try to address these concerns privately, and we did that for months. I don't know anybody -- not one person -- that wanted it to come to this, where we are right now. I certainly didn't."

Sources have said the rebels tried to talk Selinger into quitting voluntarily for the good of the party, months after he angered voters by raising the provincial sales tax, but Selinger refused.

A Tory spokesman rejected Oswald's accusation that the party is anti-woman and anti-gay.

"It's a ridiculous statement" Mike Brown said Sunday.

"I wouldn't work for an organization that is anti-woman or anti-gay. Neither would our MLAs (legislature members)."

The Tories opposed Bill 18 largely because it failed to provide real measures to combat bullying in schools, Brown said.

As for the nomination of James Teitsma, Brown said he is not a member of caucus and will only be one voice among many if he is elected.

"If and when he becomes a member of caucus, he will get a small voice in that. I do not believe that his voice is a negative one."