TORONTO - The Liberals have launched their first attack ads against their main rival in the fall election, even though Premier Dalton McGuinty has stayed away from negative campaigns in the past.

The 30-second ad features Progressive Conservative Leader Tim Hudak and newspaper comments from readers complaining that he treats voters like "dolts" and "chumps" and lacks a credible platform.

It stands in stark contrast to the Liberals' ads so far, which showcase kids, doctors and auto workers and lists the government's achievements.

NDP critic Peter Kormos says the latest ad is the kind of "low-life" negative advertising that carries the "stench of fear."

Infrastructure Minister Bob Chiarelli defended the ads, which are part of what the Liberals are calling an "aggressive" campaign, saying the party has a responsibility to point out the holes in the Tory platform to voters.

The Progressive Conservatives have already taken out ads that call McGuinty "the taxman." They first aired during Game 7 of this year's Stanley Cup final.