The Ontario budget will hike taxes for high-income earners, aviation fuel and tobacco, according to a leaked Liberal budget document.

The spending plan, entitled "Moving Ontario forward overview," was obtained by CTV Toronto. It comes ahead of Thursday's Ontario budget, a high-stakes document that could potentially force a provincial election if both opposition parties refuse to support it.

According to the leaked document, the minority Liberals plan on hiking personal income taxes for "higher-income earners."

A definition of who an upper-income earner is, and how big of a tax hike they should expect was not specified in the cabinet document.

The leaked file also says the Liberals plan on increasing tobacco taxes but does not specify how much of a hike smokers should expect.

Tobacco taxes in Ontario have been frozen since 2006 at 12.35 cents a cigarette, and generate about $1.1 billion in annual revenue for the province.

Also on the budget agenda, according to the document, is:

  • A four-cent-per-litre tax increase on aviation fuel over four years
  • Limiting tax credits for large corporations

According to the document, the tax hikes are part of the government's effort to raise $29 billion over 10 years for transit and infrastructure projects.

Premier Kathleen Wynne has previously said she would not increase taxes on the middle class to pay for the projects. She had also rejected recommendations to raise the tax on gasoline or hike the HST.

With a report from CTV Toronto’s Paul Bliss and The Canadian Press