MONTREAL - Ambiguities on the independence question were seized upon as buoys Thursday by a Charest Liberal campaign that had earlier seemed adrift.

The Liberals latched onto that familiar lifeline as their two main opponents struggled with questions about inconsistencies on the one issue that has defined Quebec politics for decades.

The Parti Quebecois explained that, contrary to what it told members months ago, citizens would not be able to automatically initiate a sovereignty referendum by raising enough signatures on a petition.

Pauline Marois explained that her party would only consider the possibility of a referendum once 850,000 signatures had been gathered.

"It will force a government to reflect deeply," Marois said of the petitions demanding a plebiscite. "Ultimately, it's up to the national assembly to decide when there will be a referendum."

She was forced to clarify that position after coming under fire in her TV debate with her old colleague, and current foe, Coalition party Leader Francois Legault.

But Legault was peppered with questions about his own ambiguous position on the independence question, such as: If he became the opposition leader, and the PQ called a sovereignty vote, what side would he campaign on?

The province's referendum law gives parliamentarians five days to join either the Yes or No side. If one side has no leader, the province's elections body is responsible for finding one from the general public.

Legault explained that he would not join either side in a referendum. Until then, he'd do everything to avoid one, he said, "We will fight against having a referendum. We don't want a referendum."

Legault's position on the national question, as expressed in the last few days, is as follows: He doesn't want a referendum. If there were a referendum, he'd vote No to independence. He wouldn't participate in that campaign. However, he also says it would be bad for Quebec if it "lost" the referendum in a No vote — an analysis he voiced during Wednesday's TV debate.

That ambiguity prompted a scolding from Liberal Leader Jean Charest.

"The moment there's a conflict on the (national question) he'll be missing in action," Charest said of Legault.

"Seats in the national assembly aren't spectators' chairs... They're not VIP seats to watch political debates."

He also poked fun at Legault's ambivalence. Charest noted at a news conference that the event Thursday was being held near Montreal's main airport.

"It must be interesting when Francois Legault passes through customs. They ask him for his citizenship and he says, 'I'm neutral.' Are you Canadian? 'Oh, no, no, no, hey, I'm not Canadian.' Are you Quebecois? 'No, no, no, no. I'm neutral.' "

Charest joked that, even if he hadn't been a participant in the previous night's debate, "I believe I had a very good debate yesterday."

The leaders of Quebec's main political parties were back on the hustings Thursday hoping televised debates might give their respective campaigns a massive boost.

The would-be premiers have just less than two weeks left to impress Quebecers before the Sept. 4 election.

Marois was perceived as the campaign's front-runner before the various debates began last Sunday, but it is unclear how the encounters have influenced voters.

The latest details about the Coalition and PQ positions on independence only emerged after Wednesday's final debate, between Marois and Legault.

The PQ also came under attack during the debates for not having released the costing of its campaign promises. The party promised Thursday to release the fiscal framework on the weekend, then pushed the date up a day and now says it will happen Friday.

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• Key Quebec Election Issues

  As Quebec begins a provincial election campaign, with a vote scheduled for Sept. 4, here are some key issues and the stated positions, so far, of the three largest parties: the Liberals, the Parti Quebecois and the Coalition for Quebec's Future.<br><br><em>With files from CP</em>

• Student Strikes

  Liberals say their $254-a-year, seven-year tuition increases will improve universities while expanded loans and bursaries programs will actually leave the poorest students better off. Liberals have mostly refused to budge in face of protests, although their original proposal was for $325-a-year increases over five years. Their controversial Bill 78 would reopen classes in mid-August for one-third of students still on strike, while setting out severe fines for anyone blocking schools.<br><br>PQ has been more supportive of protesters and would cancel the hikes, propose smaller increases pegged to inflation and hold provincial summit on university funding.<br><br>The Coalition has positioned itself to occupy the middle ground, proposing more modest annual tuition increases of $200 a year over five years. Party originally voted for Bill 78 but now says it created unnecessary tension and wants some provisions suspended.

• Ethics

  After two years of intense pressure, Charest Liberals called a corruption inquiry that is now probing malfeasance in construction industry and its ties to political parties and organized crime. Before that, they had announced plans to hire more oversight officials at Transport Department; tougher fines for engineering firms; stricter political fundraising laws; new rules for public-works tendering; and new anti-corruption squad that has since made numerous arrests.<br><br>PQ making ethics central plank of platform. It wants tougher legislation preventing companies guilty of tax evasion from winning public contracts. It also proposes new measures to combat voter cynicism including: citizen-initiated referendums, fixed election dates, political donations limited to $100 a year, and the right to vote at age 16.<br><br>The Coalition wants new integrity commissioner to oversee government contracts, and new powers for prosecutors, as part of a "big cleanup." It also promises fixed election dates.

• Northern Development

  Liberals will tout Plan Nord, a sweeping plan that sets out $80 billion in public and private investments in mining, energy, infrastructure and conservation projects over a quarter-century.<br><br>PQ accuses Liberals of selling off Quebec's natural wealth at cut-rate prices and is calling for a 30 per cent surtax on profits from non-renewable resources.<br><br>The Coalition has also taken aim at the signature plan, alleging windfall will primarily benefit foreign companies and Quebec mining firms cosy with Liberals.

• Sovereignty

  Liberals have long stood as the major federalist option in Quebec. Party is frequently accused by opponents of being subservient to Ottawa. However, it has clashed publicly with federal government over issues like long-gun registry, omnibus crime bill and changes to health transfers.<br><br>PQ is offering no timetable for third referendum on independence. Instead, party plans to pick fights with Ottawa in seeking more power over immigration, environment, agriculture and revenue collection. PQ hopes such battles will generate support for independence. Eventually, Quebecers themselves could initiate referendum, under plan to allow California-style plebiscites. People would need to collect 850,000 signatures to hold provincial vote on a given topic.<br><br>The Coalition, led by former PQ minister Francois Legault, vows to shelve any referendum on independence for 10 years to focus on building economy. But many federalists remain wary of the once-passionate sovereigntist.