Insisting she is "running to be premier" Horwath said she could not support "Liberal corruption" or the PC's plan to cut 100,000 public-sector jobs.
"This election is about choosing the change you want," said Horwath. "I think that you should concentrate and focus on what you want to see in this province and not vote out of fear."
Polls suggest the Liberals and Progressive Conservatives are neck-and-neck ahead of Thursday's vote, with a minority win by either party a distinct possibility.
Liberal Leader Kathleen Wynne has slammed Horwath for refusing to rule out supporting the Progressive Conservatives in a minority government situation. Wynne has also said a vote for Horwath is a vote for PC leader Tim Hudak. A Liberal ad released Sunday implores left-leaning voters to vote Liberal, not NDP, saying "a split vote will only help Hudak's chances."
In an opinion piece published Sunday and signed by Wynne, the Liberal leader attacks Horwath for abandoning her party's roots.
"In an effort to win just a few more seats in the legislature, Andrea Horwath has abandoned the people the NDP once professed to defend. In doing so, she’s created the very real possibility of a Tim Hudak-led government," Wynne says.
Liberals using scare tactics, Horwath says
Horwath said Monday Wynne is trying to scare voters away from voting for the party whose platform they support.
"I think that people know very well that Ms. Wynne is trying to scare their vote," said Horwath. "But people don't have to choose to support corruption. People don't have to choose to fire 100,000 people."
Horwath made her comments in downtown Toronto as she stood beside a statue of former federal NDP leader Jack Layton, who died in 2011 just months after leading his party to opposition status.
"I think that you should concentrate and focus on what you want to see in this province and not vote out of fear," said Horwath. "I don't think you should listen to anybody who tells you how to vote or anybody who tells you how to think."
Horwath said Wynne likes to talk about great NDP leaders "but she cannot even stand in their shadows" and added that she is fighting the same battle Layton waged against "Liberal entitlement."