TORONTO - The eight-month marathon that gets underway Tuesday to choose a new leader for Ontario's New Democrats likely won't yield any surprise candidates, but could open major rifts in the party's 10-member caucus among those who bid for the top job, insiders warn.

Contenders are already facing enormous pressure to organize their teams, raise hundreds of thousands of dollars to fund their campaigns and sign up new members whose votes are key to securing the leadership at the party's convention next March.

But observers say the biggest hurdle will be to find a way to redefine a party that has been living in the shadow of former NDP Premier Bob Rae for more than a decade and has stalled at the polls in the last three provincial elections.

"Their big challenge will be to come to grips with what is the New Democratic Party about at this point in their history," said Bryan Evans, a politics professor at Ryerson University in Toronto.

"I think what you might see are potentially rather different visions beginning to develop, which are maybe more ideological."

Whether the party swings hard to the left or back towards the centre in order to attract coveted urban voters, the new leader will need to give the party an edge over newcomers like the Green Party, which has gobbled up popular support in recent years, he said.

"Where do they create that edge where people who are feeling marginalized, feeling neglected, feeling alienated -- how do they attract those people again?" Evans said.

The list of likely candidates willing to answer that call has shrunk since current leader Howard Hampton, who represents the northern riding of Kenora-Rainy River, announced last month his intention to step down.

Party whip Gilles Bisson, a 51-year-old francophone who represents the northern riding of Timmins-James Bay, has made no secret of his leadership ambitions.

"I'm going to be real clear: I'm not running to be leader of the Opposition," he said Monday.

"When I run, I want to be premier. That's what this is all about, and I think that message will go a long way."

Fellow caucus members Peter Tabuns and Michael Prue -- both representing Toronto ridings -- are widely expected to run, along with Hamilton MPP Andrea Horwath. Toronto critic Rosario Marchese said he's still undecided, although he's "seriously considering" a bid.

Cheri DiNovo, a United Church minister who's made a big splash since she joined the legislature two years ago, has quashed speculation of launching a bid, saying she'll throw her support behind Tabuns.

"I know how ugly things can get and I have perhaps too much common sense to want to walk into that one again," said DiNovo, whose troubled adolescent years were ammunition in a Liberal smear campaign during the 2006 byelection.

"It was awful. It was hellish to live through, it was hellish for my family to live through. Campaigns can get ugly and I hope this one doesn't."

Prue is expected to launch his bid Friday.

Tabuns, who shares his east Toronto riding with federal NDP Leader Jack Layton, is travelling outside the country and won't return until the end of the week. Neither Bisson nor Horwath have announced an official launch date either.

Some insiders and observers have also compiled a wish list of top draft picks for the job, including Toronto Mayor David Miller -- a lapsed New Democrat -- and Ontario ombudsman Andre Marin, whose no-nonsense approach to the job of provincial watchdog has earned him a high profile as one of the government's biggest critics.

Others want to see federal New Democrat Peggy Nash lead the party, although she said Monday she has no plans to run.

Miller has also shown zero interest in the job and Linda Williamson, a spokeswoman for Marin, dismissed his potential candidacy as wild speculation, adding that Marin intends to serve out his term as ombudsman.

Jodie Jenkins, who twice failed to win a provincial seat for the NDP in Belleville, said last month he plans to run for the job. But the rules will likely prevent anyone other than serious contenders from entering the race.

Candidates will have to pay $15,000 to gain admission -- $5,000 of which will be refunded at the end of the campaign -- and provide the signatures of 100 card-carrying New Democrats from all four regions of the province, half of them women.

Campaign spending is capped at a whopping $500,000, with the party taking 40 per cent of whatever the candidates raise to offset the enormous cost of the leadership race.

Some insiders are balking at the high spending cap, which will likely steer candidates towards corporations and unions for campaign donations, rather than individual party members.

Contenders will also be racing to sign up new members before January to secure support ahead of the March leadership convention, which will give individual party members 75 per cent of the vote while labour receives 25 per cent.

The one-member, one-vote system promises to be quite lucrative for the party, which charges $25 per membership or $5 for students and the unemployed. The Progressive Conservatives and Liberals charge about $10 each, with special rates for seniors and students.

NDP officials are also planning a series of all-candidates debates -- potentially as many as 12 -- between October and February, which may end up being streamed online to reach far-flung members.

Currying favour with big labour will likely play heavily in any winning strategy. CUPE Ontario president Sid Ryan, who denies speculation that he'll launch his own leadership bid, said unions are talking about potentially backing a single candidate. If they come to a consensus, it could turn them into kingmakers come March.

"I'm trying to get them to come together, and say that labour will have much more influence if we can all agree upon one candidate," Ryan said.

"And whomever that candidate may be, then will be the one that all of labour will try to get behind and support."