Greg Selinger is the third candidate to step forward in the Manitoba NDP leadership race. (Legislative assembly of Manitoba)

Finance Minister Greg Selinger has announced his candidacy for leader of the Manitoba NDP.

He held a press conference during the noon hour on Tuesday, delivering the news to a raucous round of applause.

"I know you can grow the economy and reduce poverty while having social inclusion, while at the same time protecting the environment. None of those things are incompatible," he said. "We can, with a thousand steps, create a better world with a greener economy and social inclusion. Ten years as finance minister have taught me these lessons."

Cabinet ministers Eric Robinson and Kerri Irwin-Ross are among those who have thrown their support behind Selinger.

"I know you can make a difference for individuals, cultures and societies, and at the same time be financially responsible. I know you can invest in assets like hospitals, schools, roads, daycares and water … in a way that's sensible financially," Selinger said.

The MLA for St. Boniface since 1999, Selinger is the third candidate to join the race to replace outgoing leader and current Premier Gary Doer.

Andrew Swan, minister of competitiveness, training and trade, and Steve Ashton, intergovernmental affairs and emergency measures minister, have also said they will challenge the party's leadership.

A convention has been set for Oct. 16-17, with the new leader and premier to be named on the final day.

Doer, the provincial NDP leader since 1988 and the premier of Manitoba since 1999, surprised many political observers by announcing Aug. 27 that he is stepping down.

The following day, he was introduced in Ottawa by Prime Minister Stephen Harper as Canada's next ambassador to the United States.