TORONTO - Opposition parties say thousands of people are speaking up against Ontario's plan to merge sales taxes next year and believe there's still time to stop it.

NDP Leader Andrea Horwath says more than 50,000 people have signed her party's petition to stop the government's plan to harmonize sales taxes -- a move she calls an unfair tax grab on everyday essentials.

Horwath says she's confident those numbers will swell as more and more people understand the implications of the change, and believes there's still time to stop the plan to merge taxes before the legislation is introduced.

The Progressive Conservatives have their own online petition, with new leader Tim Hudak also taking his message of revolt to communities across the province.

New Revenue Minister John Wilkinson isn't deterred by the petitions, and says there's a give and take in the reform because the plan involves permanent income tax cuts -- a benefit people aren't always aware of.

Wilkinson says the people he's talked to so far understand the proposed new tax system reflects changing economic conditions and is meant to attract more jobs to the province by making Ontario attractive to corporations.