TORONTO -- The woman who sparked Ontario's election by rejecting what many observers described as her dream budget formally launched her campaign Wednesday with the aid of a teleprompter, a run at the scandal-plagued Liberal government, and an explanation of why she felt the need to go to the polls.

On the hustings, New Democrat Leader Andrea Horwath said she couldn't trust the governing minority Liberals to implement their budget plan, which called for higher taxes on the wealthy and billions of dollars in spending on public transit and job grants.

"I thought long and hard about the many promises the Liberals are making," Horwath said in a cafe in Kitchener, Ont., where she used a teleprompter for her stump speech.

"The same government that couldn't fulfil three promises the last year is making more than 70 new promises this year. How can (Premier) Kathleen Wynne build a ship when she hasn't managed to build a raft?"

The Liberals, Horwath said, deserve "some time in the penalty box" after what she called 10 years of scandal.

For months now, Wynne has had to deal with the fallout of a decision made by her predecessor, Dalton McGuinty, ahead of the 2011 election -- the cancellation of two gas plants -- in what the opposition parties say was a Liberal seat saver plan.

That decision is estimated to have cost as much as $1.1 billion and a police investigation is also currently underway into the deletion of premier's office emails on the topic.

Still, Wynne's campaign headed Wednesday to the riding formerly held by McGuinty, saying only that the former premier served the area well and the Liberals "have a fantastic history in Ottawa South."

Wynne pulled the plug on the legislature Friday after Horwath made it clear she would side with the Progressive Conservatives and bring down the minority Liberal government by voting against the budget.

The Tories' Tim Hudak, who has been in a libel-suit sparring match with Wynne over the gas plants, tried to position himself as the only leader with a real economic plan -- although he has been light on the details on his key promise: to create 1 million new jobs over eight years.

Both Horwath and Wynne, Hudak said on the campaign trail, were trying to play the populist card rather than advance real policy.

"The other two leaders, it's clear they're going to run a personality contest," Hudak said.

"If you want a premier who's going to have a turnaround plan, look at me. Look at my team. Look at my plan."

While Horwath's main target Wednesday was the Liberals, she also took aim at Hudak's "million jobs" plan, saying it would do nothing for regular families.

Jonathan Rose, with the political studies department at Queens University, said her use of a teleprompter -- more likely to be seen at a major formal speech -- likely follows accusations Horwath has made verbal gaffes including a hotly denied claim that the Liberals want to privatize Toronto transit.

"When stakes are higher, communications become more controlled," Rose said.

"Parties now are realizing that they need to stay on message and anything that detracts from it is a liability."

Outside the legislature, Green party Leader Mike Schreiner said it was time to restore "honesty and integrity" to provincial politics.

His federal counterpart Elizabeth May had proven herself an effective voice in Ottawa despite being the only elected Green member, Schreiner said.

About 9.3 million people are eligible to vote in 107 ridings come June 12.

With files from Keith Leslie, Maria Babbage, Will Campbell