Ontario's Liberal leader insists her attacks on the New Democrats are different from those of the Progressive Conservatives, though both are labelling the poll-leading party as "radical."

On Friday, the Progressive Conservatives alleged an NDP candidate in east Toronto, Tasleem Riaz, had made offensive comments online, including a post from 2013 misquoting Adolf Hitler, and a release sent by the Liberals on Saturday morning cites the post and describes the New Democrats as "too risky, too radical."

When asked about her use of the term — one Tory leader Doug Ford has frequently used to denounce the NDP — Liberal leader Kathleen Wynne was quick to distinguish herself from the Progressive Conservative leader.

"I'm not in any way buying into anything that Doug Ford is saying," Wynne said. "We have our own critique and our own concerns about what the NDP is suggesting."

The post surfaced as NDP leader Andrea Horwath saw a surge in the polls, pushing ahead of Ford's Tories and into first place.

On her campaign bus Saturday, Horwath said the criticism her candidates are facing is "disappointing" and unproductive.

"I don't think that people want to watch mud be slung by the parties," she said. "The Conservative party and the Liberal party should think about the fact that when you throw mud, you lose ground."

Horwath directed the bulk of her complaint towards Wynne.

"Kathleen Wynne basically said if Doug Ford goes low, she's going to go lower," Horwath said. "I don't think that's leadership."

At a campaign event in Toronto, Wynne said she isn't going low — she's calling it like she sees it.

"I'm not going to go low or high, I'm going to go right down the centre and talk about what's actually happening," she said. "I'm going to name what is happening."

Wynne said that as a serious contender in the June 7 election, Horwath should be prepared to face scrutiny.

"I can tell you from lived experience: being taken seriously means that you've got to answer tough questions," she said.

Horwath called attacks on her candidates "disappointing" and said they could make people cynical about politics.

"It paints a picture that politicians only care about attacking one another and lose sight of what the job is supposed to be," she said. "I think it's what turns people off voting."