When Quebec's new finance minister, Nicolas Marceau, delivers his first-ever budget on Tuesday afternoon, it will be the first time in nearly a decade the Parti Québécois will be the ones calling the fiscal shots in the province.

As with any budget, it will lay down the blueprint for the way billions of dollars will be spent and collected. But, unlike most budgets in the province's (and indeed the country's) history, this fiscal plan will be the product of a minority government.

Not business as usual

The Marois government is stickhandling Quebec's bloated financial puck around two big obstacles. The first is the rattled nerves of international bond rating agencies, which have been expressing low-grade consternation ever since the election of the PQ to power in September.

Quebec has by far the highest debt-to-GDP ratio in Canada, and therefore relies heavily on borrowing money to keep the wheels of public services going 'round. If ever Quebec's credit rating were to be downgraded, interest rates on that gargantuan debt would rise, forcing the province to pay even more just to manage that debt, never mind actually beginning to pay it down.

So, the budget will aim to placate those nervous financial analysts, and demonstrate public finances are in responsible hands. That means maintaining the target of ending deficit spending on schedule by the spring of 2014.

This will be no easy task, given a revenue slump due to a slowing global economy, combined with a "surprise" operating shortfall for this year which so far has reached $1.6 billion.

How to get there?

The PQ finance minister and other members of the government have already proposed and then backtracked on a series of measures meant to redress this uncomfortable situation.

Right after the election, they floated a retroactive tax hike for the most well-off Quebecers. And then, suggestions of a steep increase in royalty revenues to cash in on burgeoning northern resources development. Both ideas were scrapped after a firestorm of criticism.

So, with Tuesday's budget, the government will nevertheless seek to reach that same goal with a softer touch. An upper-income income tax hike, perhaps, along with an adjustment of a $200 per year flat tax for health services, so the poorest pay nothing, while the richest pay more.

These measures are as much about fiscal expediency as they are about ideology. The PQ are social democrats, the core of the party's support base believing strongly in a more equitable redistribution of wealth.

The political uphill climb

But it is also about appeasing opposition parties, which cannot universally reject the budget without risking bringing down the nascent PQ government and triggering a snap election most would consider outrageous only a few months after the last one.

While the Coalition Avenir Québec led by former PQ cabinet minister (and finance critic) François Legault has vowed to vote against any budget containing tax increases and/or service cuts, the opposition Liberals find themselves in a different position.

Without a permanent leader since the defeat of Jean Charest on Sept. 4, the Liberals are in no practical position to fight an election, even if the moment were otherwise opportune. Their leadership convention is still four months away. And the afterglow of their defeat and loss of power remains fresh.

How far will the PQ go?

That reality is what will guide the Parti Québécois' choices as laid out in Tuesday's budget: to push the party's agenda as far and as fast as possible, knowing right now is perhaps the one and only time they can be all but certain to avoid defeat, while not introducing a budget so outrageously contrary to the other party's wishes as to spark irrational revolt. Because, after this budget, and the Liberal leadership vote next spring, it will be open season on the PQ government of Pauline Marois.