TORONTO -- Ontario's opposition parties are at odds over a motion to test the confidence of the minority Liberal government.

The Progressive Conservatives plan to introduce the motion in the legislature today, in part to force the New Democrats to stop propping up the Liberals.

The Conservative motion, which will be debated next week, will ask if the government and Premier Kathleen Wynne have the confidence of the legislature.

However, it's not a true confidence motion, so the results would not be binding on the government, but it would be a test of the Liberals' standing with members.

But NDP Leader Andrea Horwath dismissed the motion as a gimmick that the Tories know doesn't have a chance of toppling the government.

She says Tory Leader Tim Hudak is just playing games.

The Tories say the Liberals wasted more than $1 billion to cancel gas plants to save seats in the 2011 election and no longer have the moral authority to govern.

Just last week, the Tories introduced a motion to force the Liberal party to pay back the money spent on the cancelled gas plants, a motion the New Democrats supported.

However, the Tories failed to have enough members in the house for the vote, so the Liberals were able to defeat the motion by a single vote, 27-to-26.

PC insiders vow that won't happen when the vote on the confidence motion comes up next Wednesday, saying they want the legislature to clearly express a lack of confidence in the Liberals.

Hudak wrote an open letter to Horwath on Sunday, saying he was "shocked" the New Democrats were not fed up with the Liberals' behaviour and ready to try and bring down the minority government.

"The moral bankruptcy and corruptness of the Liberal government of Ontario is now patently obvious to the majority of Ontarians," wrote Hudak.

"I remain somewhat astounded that you and your party don't grasp that continuing to prop up the Wynne government by being at its beck and call is doing Ontario no favours."

Hudak says he hasn't received any response from Horwath to his letter, which also requested a meeting with the NDP leader "sooner rather than later."