MONTREAL -- Francois Legault dubbed Parti Quebecois Leader Pauline Marois the "queen of the status quo" on Wednesday as the two former PQ colleagues clashed in a televised debate.

Legault said he would slash bureacracy if he became premier on Sept. 4, including cuts to Hydro-Quebec and in the education sector.

The leader of the Coalition for Quebec's Future accused Marois of being beholden to Quebec's powerful unions.

"You are the queen of the status quo," Legault told his former PQ colleague. "It's sure that nothing will happen with you (in power). Both your hands are attached to the unions. No positions will be abolished... It will be the statis quo."

Earlier, the two politicians, who spent nearly five years in cabinet together, opened their televised tussle by each promising integrity if they become premier next month.

Their clash is the last of four consecutive debates featuring the province's political leaders.

Marois and Legault were to debate four topics: governance, social policy, the economy and the national question.

Marois kicked off the highly anticipated encounter by telling Quebecers that a PQ government would be clean.

"You have in front of you two very different visions of Quebec," she said. "My vision is to present an honest and responsible government. And we are going to do that with Quebecers."

With corruption a hot-button issue in the campaign, Legault didn't want to let his PQ rival occupy centre stage on the issue.

"I think what Quebecers want is a clean and efficient government that stands up to interest groups," Legault told viewers. "The priority in Quebec is a major cleanup to get rid of corruption and waste."

The clash between the two was expected to have some extra spice because of their past, which included spells together in the cabinets of Lucien Bouchard and Bernard Landry.

Marois was to make a run for the PQ leadership in 2001, but backed out after being abandoned by none other than Legault, who threw his support behind Landry.

The previous head-to-head debates this week saw Marois duelling with Liberal Leader Jean Charest on Monday, and Charest duking it out with Legault on Tuesday.

One of the more interesting aspects of the Marois-Legault debate was to be their exchange on sovereignty referendums.

Marois is constantly vague on the timing of the next one, while Legault says he will not hold a referendum for 10 years and that he would even vote No if one were held right now.