In an interview with CBC Radio's The House, Horwath told host Evan Solomon there's a 50-50 chance she'll either prop up Kathleen Wynne's Liberal minority government or reject the budget, which would trigger an election.
"It could go either way," Horwath said.
While Wynne's Liberal budget included many NDP goodies such as a promise to reduce auto insurance rates by 15 per cent on average for nine million drivers, Horwath said the New Democrats were hoping to see more in the way of fiscal responsibility and accountability.
"The budget did reflect a number of things that we did talk about with Ontarians in terms of priorities, but unfortunately the government didn't see their way to implementing some of the cost-saving measures we suggested and we're quite concerned about that."
Conservative Leader Tim Hudak made it clear before the budget was ever tabled that his party would not be supporting a Wynne budget, saying Thursday that "the only way to put Ontario on the right track is a new team with a new plan and the courage to put it into action."
Meeting with Wynne
Factoring into Horwath's decision will not only be the feedback she is seeking from Ontarians but also the outcome of a meeting with the premier this week.
"We will be meeting with Ontarians over the next couple of days and then I'm sure there'll be an opportunity for myself and the Premier to discuss the matter."
Horwath said she would like to see "real accountability measures" included in this budget.
Ontario Liberals, for instance, have set a five-day “target” wait-time for home-care but Horwath said targets are not good enough.
"We, of course, want to see a guarantee."
"What we really want to do is deliver results. We don't want lip service paid to our ideas just so that the Liberals can stay in office — that's not delivering real results," Horwath said.
Another consideration for Horwath is the Liberal's decision, under former Ontario premier Dalton McGuinty whose cabinet Wynne was a part of, to scrap the development of two gas plants in Mississauga and Oakville, Ont., which could cost taxpayers up to an estimated $585 million combined.
"One of the things that we are quite concerned about is the government's track record in terms of actually delivering on their promises," Horwath said.
"We think it's important to make sure we hold them to the highest account because they have proven time and time again that they're more interested in their own fortunes than they are about the people of this province."
Complicating matters further for Horwath are polls which have the New Democrats running behind Hudak's Progressive Conservatives and Wynne's Liberals.
Another consideration weighing on Horwath is the possibility that, should an election be triggered and those polls hold true, Ontarians could be putting Hudak's PC's in power.