Ontario's election frontrunners spent Saturday trying to break through a virtual dead heat between the Liberals and the Tories.

With less than a week to go until voting day, a Nanos Research poll for CTV, CP24 and the Globe and Mail shows the Liberals at 37.7 per cent support, the Tories at 33.4 per cent and the NDP at 25.5 per cent.

Dalton McGuinty's Liberals and Tim Hudak's Progressive Conservatives are veering into minority government territory, leaving Andrea Horwath's New Democrats in a possible decision-making role.

Horwath acknowledged her position as potential election kingmaker in Kingsville Ont., where she told an audience that she's getting ready to outline her priorities for forming a minority government.

"We're going to be a little bit more specific in the next day or so about what we want to see as priorities if we were to form a government in this province," she told a crowd at the campaign spot.

While Horwath didn't say which party she'd support in a minority government situation, she said the NDP will be "making very clear" what they'd like to accomplish.

Meanwhile, Dalton McGuinty's Liberals have taken aim at their Tory rivals ahead of the tight contest on Oct. 6.

The party has prepared a 30-second TV ad that plays on fears the Progressive Conservatives may slash health-care funding if elected.

In the ad, a frowning Hudak is shown beside Prime Minister Stephen Harper. A narrator then compares Hudak to former PC premier Mike Harris, who closed several hospitals during his time in power.

The advertisement is set to be broadcast in the next few days.

Hudak spent his Saturday in Ontario's Hamilton and Niagara areas, where he's pledged to build a highway if elected.

"A good highway route like that would not only create jobs in building it, but most importantly will attract new businesses to our area and help to break the gridlock," he told reporters.

Some Niagara-area residents have opposed the project, calling it a waste of money.

The exact location of the highway hasn't been determined, though Hudak has said it will probably start along the Queen Elizabeth Way outside of Fort Erie, Ont., heading west, and south of the Niagara escarpment toward the Hamilton airport.

With files from The Canadian Press