Despite heavy criticism from labour groups and party members accusing her of leaning too far to the political right, NDP Leader Andrea Horwath is standing firm on her decision to trigger an election, saying Ontarians "need to be given the opportunity to make a choice" at Queen's Park. 

Leaders of large unions have taken aim at Horwath after she announced the NDP would not support the Liberals' budget, which was unveiled earlier this month.

On Friday, 34 high-profile current and former New Democrats sent Horwath an open letter to say they were “angry” with her for not supporting “the most progressive budget in recent Ontario history.

“From what we can see you are running to the right of the Liberals in an attempt to win Conservative votes,” the letter says. “It is not clear whether you have given up on progressive voters or you are taking them for granted.”

Earlier in the week, Unifor President Jerry Dias publicly questioned the NDP leader's decision to provoke an election after the Liberals unveiled what many viewed as a labour-friendly budget.   

"Mr. Dias is welcome to his opinions, but I think what we need to realize is that Ontarians need to be respected, and they need to be given the opportunity to make a choice," Horwath said in an interview that aired on CTV's Question Period on Sunday.

"I'm just saying I don't think people necessarily like to be told, I think people like to make their own decisions, and that's what they're going to do on June 12," Horwath added.

After propping up the Liberal government for the past two years, Horwath maintains she no longer has "faith" in the scandal-plagued Liberals to keep their promises.

"One of the things I've been trying to do is show people that they have a choice, that it's not inevitable to have the Liberal government back," Horwath said on Question Period.

Horwath, who unveiled her party's platform this week in Toronto, is also defending her party against the notion that the Ontario NDPs are poor fiscal managers, a view that dates back to the turbulent years in the 1990s when the NDP was in power under Bob Rae. 

"NDP governments have run fewer deficit budgets than the other parties and our deficit budgets historically, have been lower in terms of the ratio to the GDP," Horwath said. "In other words, our track record is quite good when it comes to all of the NDP governments across the country over time."

Horwath said former Saskatchewan Premier Roy Romanow, former Manitoba Premier Gary Doer, and founding NDP Leader Tommy Douglas, were good managers of the public purse, and if elected, she would follow in their footsteps.

"Being prudent on fiscal matters is something that is in the DNA of New Democrats and that's in my DNA as well," she said.

The NDP platform revealed a number of initiatives, including a "modest" increase in the corporate tax rate, a cut to auto insurance premiums and interest-free student loans.

Also in the platform, Horwath said, is "a significant contingency built into that plan to make sure that should there be any unexpected curves, we can still meet our promises and maintain our target to be balanced by 2017-18 in terms of the deficit."

Horwath also said the plan "saves more than it spends" on an annual basis, noting the NDP pledges to "cut out some of the fat" by collapsing hydro agencies into one organization, removing bureaucracy and capping public sector CEO salaries.

Three weeks to election day, and Horwath's third-place NDP appear to be gaining momentum. An Ipsos Reid/CTV News poll conducted this week showed a 4 percentage-point gain for the NDP, while the popularity of the frontrunner PCs slipped. Ontarians surveyed also favoured Horwath as the party leader they believe would be best for the job of premier.