Stephane Dion's "green shift" carbon tax plan would cut taxes by $15.5 billion, including $11 billion in personal income tax cuts, CTV News has learned.

The income tax reduction is to make up for the $15.5 billion levy on carbon, aimed at reducing greenhouse gases in Canada.

The proposed green tax will hit electricity and home heating fuel but exempt gasoline. The Liberals have acknowledged that oil companies may pass the cost of the tax on to consumers.

The Liberal leader's proposal is due to be released Thursday. A carbon tax plan is seen as risky by many analysts, as Dion is betting on the Canadian public's desire to reduce greenhouse gases to outweigh a potential rise in costs.

Here's how the tax brackets that will be affected by the Liberal's plan:

• one per cent cut in the general tax rate, from 15 per cent to 14 per cent

• 1.5 per cent cut to the rate for the lowest tax bracket from 15 per cent to 13.5 per cent. This affects people earning $37,885 or less.

• one per cent reduction for the second-lowest tax bracket ($38,885 to $75,769), from 22 per cent to 21 per cent.

• one per cent cut in third-lowest income tax bracket ($75,769 to $123,184) from 26 per cent to 25 per cent.

Dion will ask the Auditor-General to report annually on the carbon tax, and confirm that it is revenue neutral.

The carbon tax would be phased in over four years.

'Shift happens'

On the eve of Dion's announcement, the Conservatives took ample opportunity to shots at the plan.

Tory MY Jason Kenney said that with a carbon tax, Canadians will be "shift out of luck."

He also used Air Canada's recent job cuts of 2,000 to knock the Liberals saying that Dion's message to those employees would be "shift happens."

Green Party Leader Elizabeth May announced her party's carbon tax proposal on Wednesday. Her plan would impose a carbon tax of $50 per tonne of greenhouse gas.

The Liberal plan is expected to be much more moderate, and May's timing may help Dion with voters.

Liberal environment critic David McGuinty called May's plan "excessive."

He said the Liberal plan "is going to be a very middle-of-the-road and very, very realistic plan going forward."