HAMILTON - Ontario's New Democrats must take the province back from the Liberals to stop the loss of manufacturing jobs and foce issues that matter to working people back to the forefront, the party's newly minted leader said Sunday.

Andrea Horwath, who won a four-candidate race to become the first woman to head the provincial NDP, said she wanted jobs created in the steel and auto sectors, and planned to fight for public child care.

"In (Premier) Dalton McGuinty's Ontario, more than 300,000 of these well-paying jobs like the ones at Stelco ... have been lost," Horwath told hundreds of rowdy supporters in Hamilton.

"In our Ontario, these jobs will be found anew."

The 46-year-old Hamilton-born daughter of an auto worker laid out her vision on International Women's Day after winning the leadership on Saturday with 60.4 per cent of the vote.

Horwath beat out three fellow caucus members as delegates embraced her youth, energy and promise to rebuild the struggling party.

"She's our first woman leader, she comes from the next generation of leaders in our country, she has deep local experience, deep local roots in the community," said federal NDP Leader Jack Layton.

"As people get to know her and hear her speak about the issues, they're going to be very excited about the kind of leadership that she can provide."

Horwath promised to hold the Liberal government to account when it comes to job losses. She also championed the need for an industrial hydro rate, buy-local policies and light-rail transit.

Her new role, she said, will give her "an excellent opportunity" to grow the party.

David Christopherson, federal NDP member for Hamilton Centre, said Horwath had "all the ingredients" to be a good leader, including intelligence, passion and an ability to connect with people.

"The whole party is really enthused about what this means and it can only raise the level of debate in the Ontario legislature," Christopherson said.

Horwath herself quipped on Saturday that her win will turn the NDP into the official opposition given last week's resignation of John Tory as Progressive Conservative leader.

New Democrats kicked off their convention on Friday -- a day after Tory suffered a crushing defeat that left Ontario's official opposition leaderless and promised to spark a tumultuous race to replace him.

"The Conservatives will be partly in disarray and a lot of their leading figures will not be in Queen's Park," said Graham White, a political science professor at the University of Toronto.

"It will be easier (for the NDP) to make a mark given that the Conservatives won't be as prominent a force as they normally would be."

McGuinty called Horwath on Saturday to congratulate her and joked she should take six months off.

"I told him no way."

Despite the enthusiasm exuding from the leadership convention, observers pointed out that Horwath has yet to lay out a plan to achieve any of her ambitious goals -- and her promises come with no guarantee the NDP can make any gains by the 2011 election.

She is also the candidate who used the most traditional party language, even though she promised to rebrand the NDP.

Christopherson dismissed the criticism, echoing Horwath's suggestion that she simply brings a good mix of old and new.

"It might look a little like reaching out to yesterday, but for the party, it was a reaffirmation that the principles that caused people to join the NDP in the first place are still there with her," Christopherson said.

"The challenge now is to maintain the support and solidarity of the party, turn and face the population of the entire province and offer those principles in way that makes sense."

Horwath replaces Howard Hampton, 56, who took over from former premier and now federal Liberal MP Bob Rae in 1996.

He led the party through dark years that saw the NDP hurt badly by strategic voting, even losing official party status in 1999 and again after the 2003 election.

It was Horwath who helped the party regain its status when she won a byelection in her Hamilton Centre riding in 2006.

Her closest rival for the leadership was Peter Tabuns, a former Greenpeace director considered the establishment candidate, who reaped 39.6 per cent support.

Among the other two candidates, Gilles Bisson, who lost out in the second round of voting with almost 25 per cent of the vote, crossed the floor to throw his support to Horwath.

Michael Prue dropped off in the first round with just 11 per cent of the vote.

Nearly 1,200 NDP members attended the weekend convention, with 11,150 members of the 25,000 eligible voters voting in advance.