OTTAWA — Who knew it would come to this?

As the federal election campaign winds down and voting day looms, there's one question being asked in every backroom in Ottawa: if the Conservatives win, will it be a minority or a majority?

A lot depends on the answer.

If Stephen Harper ekes out a majority, no matter how slim, he has a chance to be his own man as prime minister. With a minority, everything depends on whether he can tailor his legislative agenda to meet the demands of others.

The differences between those scenarios could be enormous -- affecting how much and what kind of taxes Canadians pay, who gets to marry whom, how long people wait for medical care, and whether there is fiscal peace or war between Ottawa and the provinces.

Start with the dollars-and-cents issues.

Harper's first priority if he forms a government would almost surely be his economic platform, highlighted by promises to slash the GST and offer families with young children a child-care tax credit.

It certainly wouldn't be same-sex marriage -- an issue on which he has promised an eventual free vote, but which could also revive fears that Harper has a hidden far-right agenda on social issues.

"If he gets elected as prime minister, it won't be because the No. 1 pressing issue is same-sex marriage," said a Tory insider speaking on condition of anonymity.

"You want to get some early wins on the board to show you're making progress, and those wins will come through the economic items."

Harper's GST and child tax credit promises are not without a potential downside.

The price of cutting the GST would be cancelling Liberal income tax cuts for low- and middle-income brackets. Financing the child credit would mean abandoning some Liberal transfers to the provinces that help fund day care.

The new measures would sail through with a Tory majority. In a minority Parliament, however, they could spark endless haggling -- particularly with the Grits and NDP.

"It would enable (Harper) to make all the changes he has promised on taxing and spending," said Heather MacIvor, a political science professor at the University of Windsor.

"Money bills are crucial, and with a majority you can get those suckers through."

A majority would also solve one of Harper's greatest dilemmas -- the prospect that, in the face of Liberal and NDP hostility, he might have to turn to the Bloc Quebecois for support in the Commons.

Almost by definition, the Conservatives would have to win seats in Quebec to form a majority government. Having Quebec Tories at the cabinet table would eliminate the perception that they have to pander to the Bloc to stay in power.

"It would essentially sideline the separatists," said Faron Ellis, a political scientist at Lethbridge Community College and onetime activist in the old Reform party, which never managed to expand beyond its western base.

"Just four or five seats coming out of Quebec could be huge (for the Tories). It would fundamentally change the character of the government and of Parliament."

It could also strengthen Harper's hand in his promised negotiations with all the provinces on the so-called fiscal imbalance, a euphemism for provincial demands for ever-greater tax transfers from Ottawa.

Harper would also face delicate talks with the provinces on another topic, his pledge to reduce wait times for health care. Again, his hand would be stronger with a majority.

The situation isn't as clear-cut for the issue that could be Harper's biggest political headache -- same-sex marriage.

His promise of a free vote on rolling back the rights of gays and lesbians would likely be a formality in a minority House, given the opposition to the move among NDP, Bloc and most Liberal MPs.

A Tory majority, however, could change everything -- not least the mindset of Christian evangelicals and others in the party's social conservative wing.

"Harper would have a better shot at keeping his party in line if they're on a tight leash in a minority government," said David Docherty, a political science professor at Wilfrid Laurier University in Waterloo, Ont.

"If they've got a majority you'll have some folks out there who think it's open season. They'll say, 'We can do whatever we want.'"

Some moderate Tories dispute that claim, arguing that electing a majority government -- or even a strong and stable minority -- would necessarily mean broadening the base of the party.

"The backbone would not be people who champion the traditional definition of marriage," insisted one strategist. "We'd have more fiscal conservatives and social liberals in the pack."

Others are far less certain.

Lethbridge's Ellis, for one, said he thinks Harper's handling of the issue will be crucial for his newly minted image as a political moderate.

"It will be one of the litmus tests of whether the more rabid social conservative forces within the party are in check," he said.

"How much of the Liberal fear-mongering was true, and how much wasn't?"