Make the rich pay, NDP Leader Andrea Horwath said Tuesday in naming her price for supporting the minority government’s budget — and avoiding another election.

Ontarians should be hit with an extra two percentage points of income tax on incomes above $500,000 to fund relief for others, she urged in the first of several proposals for Premier Dalton McGuinty to consider.

Instead, the Liberal government dismissed the surtax idea as a public relations “stunt” and said it’s bad form for the NDP to dribble out its shopping list.

“Today, the NDP kicked off the start of a new spending spree,” House Leader John Milloy said in a statement.

“This is no way to balance the budget, or discuss the passage of one . . . the public and Parliament deserve to know the full extent and cost of the NDP demands.”

With Tim Hudak’s Progressive Conservatives vowing to oppose the budget, Horwath and her New Democrats are in the driver’s seat as the Legislature hurtles toward a vote by April 25 — and a possible late May election as all three parties remain millions in debt from last fall’s campaign.

Horwath said the high income surtax would raise $570 million to cut the provincial portion of the HST on home heating, create 4,000 day care spaces and boost social assistance payouts under the Ontario Disability Support Plan by 1 per cent.

“If we have to choose between helping a working mom who needs child care in order to keep her job and a high . . . six- or seven-figure salary person cashing in on an even greater paycheque every year, I think the choice should be very easy,” Horwath said.

The tax on incomes above $78,000 is now 11.16 per cent and would rise to 13.16 per cent for portions of income above $500,000 under the NDP plan, which notes the average household income in Ontario is $70,000.

Horwath’s idea also fell flat with Conservatives, who say last week’s budget from Finance Minister Dwight Duncan didn’t go far enough on job creation and restraint in the face of a $15.2 billion deficit this year.

“A tax increase of any sort is a tax increase,” said Tory finance critic Peter Shurman (Thornhill).

Horwath said she is not “drawing a line in the sand” on her tax proposal but wants to see how the Liberal government reacts to it and others yet to be revealed in the weeks to come if an election is to be avoided.

“They have a job to work with us in order to move their agenda forward. If they’re not prepared to do that, then everybody knows what the result is going to be.”

Horwath wouldn’t comment on what her fallback position would be if the high income surtax — which was not in the NDP’s election platform last fall — doesn’t catch on.

Earlier in the day, McGuinty visited a Roots garment factory in northwest Toronto and said he hopes to avoid an “unnecessary and expensive election” as the province aims for a balanced budget by 2018 and seeks to avoid a credit downgrade.

“I’ve made it very clear to Ms. Horwath and her colleagues we’re not prepared to entertain any proposals for new spending,” he said.