The leaders of two of Ontario's main political parties trumpeted major campaign promises Wednesday -- lower gas prices and subsidized child care -- but were vague on the details.

Doug Ford promised to cut gas prices by 10 cents a litre if his Progressive Conservatives win the election, but he wasn't clear on how he would replace the lost revenue from cutting the provincial gas tax and scrapping the cap-and-trade system to achieve his pledge.

NDP Leader Andrea Horwath, meanwhile, wouldn't provide details of what families earning more than $40,000 would pay for child care under her plan for the province.

The NDP is proposing to fully subsidize public, licensed, not-for-profit child care for those lower-income earners if elected next month.

Households earning more than $40,000 would pay an average of $12 a day, but the NDP has not given details about exactly what people earning more than that would pay, what specific income brackets would be established, or any caps.

Horwath was asked several times for those details Wednesday, and would only say that it is a "sliding scale."

"At some point a person's income is going to be such that they don't need to have any subsidy or any help with paying for child care," she said, without elaborating on what point that would be.

"The point is to provide affordable childcare that's high quality, that's not for profit, for the vast majority of everyday families that need that help."

The NDP child-care plan also proposes to increase wages for early childhood educators and add 202,000 new not-for-profit, licensed, affordable child-care spaces.

In Oakville, Ont., Ford stood outside a gas station to announce that he would reduce gas prices by 10 cents per litre.

He said he'd do so partly by scrapping the province's cap-and-trade system, which puts a price on carbon and has added 4.3 cents a litre to the price of gasoline.

Ford said he would also cut the provincial gas tax by 5.7 cents a litre. Currently, drivers pay 14.7 cents per litre of gasoline in provincial tax and 14.3 cents on diesel. The Tories would reduce both taxes to nine cents per litre, which they say would mean drivers pay $1.19 billion less per year.

But that also means that money isn't going to provincial coffers, along with $2 billion that the province brought in from cap and trade last year.

When asked how he would make up for the lost revenue, Ford said, "we can't afford not to do this."

"(Drivers) are frustrated at being gouged at the gas pumps," he said. "This will stimulate the economy when we put money back into their pocket. We aren't putting it anywhere else ... They'll go out and shop, stimulate the economy."

Municipalities receive two cents per litre from the provincial gas tax, and the Liberal government announced last year that they would increase it in 2019 to 2.5 cents a litre, up to four cents by 2021 -- increases the Tories would maintain.

Liberal Premier Kathleen Wynne spoke Wednesday about her record on the economy, saying that since 2003, when the Liberals came to power, Ontario has created nearly one million jobs.