TORONTO - The New Democrats kicked off their election campaign Friday with a promise to phase out the provincial portion of the harmonized sales tax on gasoline prices, appealing once again to voters' pocketbooks.

Leader Andrea Horwath, who will present the bulk of her campaign platform at a rally Saturday, said that while big themes will be present, the affordability of everyday life will remain a key priority.

"One of the things that has been forgotten in this province is the everyday people and their everyday needs," Horwath said.

"Vision, yes, is important, but keeping your feet on the ground and remembering who it is that you're here to serve is extremely important as well."

The NDP's latest promise involves reducing the tax on gasoline by one per cent every year, a move that would save a family with two children $135 annually.

To pay for the plan, which will cost $500 million, the NDP said it would shift some of the tax burden back to businesses.

The New Democrats have already promised to cap gasoline prices, remove the province's chunk of the HST from home heating and hydro bills, stop fare hikes for public transit, and remove ambulance fees for people who need to be transported to hospital.

Horwath didn't provide specifics about how businesses would pay for the HST cut on gas beyond paying higher corporate taxes, saying the details will be in the platform.

The gasoline plan would also require co-operation from the federal government, which would have to be involved in any negotiations about HST exemptions.

The province can provide exemptions of up to five per cent of the federal GST base in Ontario, but that room has already been used up by the governing Liberals.

Revenue Minister Sophia Aggelonitis said the government had already worked to remove the tax from certain goods and services, and has maintained a clear and consistent position on the HST -- unlike the New Democrats.

"The NDP have said at one point that they wanted the HST completely off gas, then they say let's regulate the industry, then they said one per cent," said Aggelonitis.

"The fact of the matter is, I'm not really sure where they're really going to stand tomorrow."

Progressive Conservative critic Jim Wilson, whose party has promised $3.5 billion in tax relief for the middle class in their platform, said the NDP seemed to be following his party's lead when it comes to giving people's pocketbooks a break.

But the NDP has yet to explain how they will pay for those tax breaks, he added, and until they clarify the costing in their platform, those promises just sound like more taxes.

"The only room they've given themselves so far is to hike taxes on the job-creators by hiking corporate taxes," said Wilson.

"That gives them about $2 billion. Anything over $2 billion means there's going to be NDP taxes."

Horwath, whose party has nominated about 70 candidates so far and is riding high after a strong showing by the federal NDP in last month's election, stood by her platform, which she said will set the New Democrats apart from all other parties.

"It's a matter of people looking at the choices they have and determining who is it that offers the real change and who is it that's ingrained in the status quo," she said.

"We're prepared to break out of to make sure that people are actually first on the agenda for a change."