With some 1,700 delegates set to choose Sunday between Selinger, Theresa Oswald and Steve Ashton, all three camps were busy trying to coax and cajole any undecided delegates to their side. Campaign volunteers were busy meeting one-on-one with delegates in the hallway of the hotel convention centre. Others worked the phones in the candidates' offices.
"About 80 per cent of the people have made their decision (for) the first ballot, but 20 per cent are in play," Jim Rondeau, chair of convention planning for Ashton's campaign, said.
"And so right now, we're trying to convince those 20 per cent to vote the right way."
The race is by all accounts too close to call, and the three camps agree it will almost certainly require a second, unpredictable ballot between the top two finishers.
Wooing delegates from the third-place camp for the second ballot will be key, said Anna Rothney, campaign manager for Oswald.
"We've got people lined up on the floor to hopefully hand out lots of Theresa stickers to supporters of whatever candidate drops off (the first ballot)."
The vote Sunday is the culmination of a caucus revolt that erupted last October when Oswald and four other senior cabinet ministers suggested Selinger resign to help the party survive the next election, which is slated for April 2016. Recent polls suggest the NDP are near record-low levels of public support, far behind the Opposition Progressive Conservatives, after raising the provincial sales tax in 2013.
Selinger refused to resign and called for a leadership contest at the party's annual convention. The decision meant his opponents would have to run against him — and win — to oust him.
Ashton, a former cabinet minister who did not take part in the caucus revolt, has attracted the most support from delegates elected at constituency meetings across the province over the last month. Oswald swept youth delegate selection and has the support of many staffers who used to work in the premier's office. Selinger secured endorsements from the province's biggest union leaders, although it is far from clear how many of the roughly 300 union delegates will follow their leaders' wishes.
Those union votes, along with almost 200 so-called automatic delegates — elected New Democrats, members of the provincial council and others — are the wild cards in Sunday's vote.
Paul Thomas, professor emeritus of political science at the University of Manitoba, said given the acrimony of the campaign, many supporters of the third-place candidate may not vote on the second ballot and simply leave.
Oswald and others who went public with their challenge to Selinger were accused last fall of "political treason" by Selinger supporter Paul Moist, head of the Canadian Union of Public Employees.
Some Oswald supporters have bitter feelings toward Selinger, Thomas said, because they feel he stubbornly stayed in the premier's chair as the party continued to slide in opinion polls.
Selinger showed some strength Saturday when Ovide Mercredi was elected NDP president. Mercredi, a former chief of the Assembly of First Nations, was backed by Selinger. He won narrowly over incumbent president Ellen Olfert, who was backed by Oswald.