McGuinty shocked the province in October when he announced his resignation and prorogued the legislature indefinitely amid controversies over his government's decision to cancel two gas plants and the Ornge air ambulance scandal.
While his resignation triggered a Liberal leadership race that will culminate with a new premier being chosen on Jan. 26, it is his government's threat to use the contentious Bill 115, which allows the government to impose new collective agreements on teachers and ban strikes, that could cause serious labour unrest in the new year.
The minority Liberal government gave teachers in the public system until Dec. 31 to negotiate contracts with school boards modelled on agreements signed with Catholic and Francophone boards, which froze the wages of most teachers and restricted their ability to bank sick days.
Public elementary teachers began job action in the fall and launched rotating one-day strikes prior to the Christmas break, with the government threatening to use the legislation to end any walkouts that lasted longer than 24 hours.
High school teachers did not stage strikes, but withdrew from all extracurricular activities. They vowed that if the government does impose new two-year agreements, the boycott would remain in place for the entire two years, while elementary teachers said they would step up their protests against the legislation.
Ironically, it was McGuinty's attempts to engineer the majority government he was denied by one seat in 2011 that turned the teachers' unions _ who used to spend millions of dollars helping Liberals get elected _ against him.
McGuinty lured away veteran Tory Elizabeth Witmer with a plum job as head of the Workplace Safety and Insurance Board, freeing up her Kitchener-Waterloo seat for a September byelection. He then recalled the legislature for an emergency session in August to pass Bill 115, which he said was needed to avoid teacher strikes right after Labour Day.
Teachers were furious over what they said was an unconstitutional move to take away their right to fair bargaining and worked hard in the byelection to ensure the New Democrats won the seat for the first time ever, denying McGuinty his majority in the process.
Late in the year, the Elementary Teachers' Federation of Ontario offered a temporary truce if Education Minister Laurel Broten waits until a new premier is chosen before she imposes new contracts on its members, but there was no indication she would accept the offer.
Only one of the seven Liberal leadership candidates _ former provincial education minister Gerrard Kennedy _ has promised to repeal Bill 115. But most have suggested they would move to recall the legislature in February with a Throne Speech, likely followed within a month by a provincial budget.
Many observers believe the budget could be defeated, triggering another provincial election. But that's not the only option.
After successfully convincing the minority government to twice change its budget last spring _ to add a tax on incomes over $500,000 and to scrap a scheduled reduction in Ontario's corporate tax rate _ the NDP say they'll try to do that again in 2013.
"Some people would prefer to be writing their election platforms right now, gearing up for an election, but New Democrats have always been more interested in getting results for people," said NDP Leader Andrea Horwath.
"I’m not clamouring for an election like the other folks. What I’m doing is actually taking my time to listen to Ontarians."
Progressive Conservative leader Tim Hudak said he's not convinced the legislature will be recalled before an election, especially after one of the leadership front-runners, Sandra Pupatello _ who did not run for re-election in 2011 _ said she wouldn't want the house sitting without her in it to lead the government side.
The Conservatives have been acting as if they expect an election in the spring, releasing a series of white papers outlining potential policy platforms such as privatizing lotteries, casinos and liquor stores, cutting the size of the civil service and reducing public sector pension benefits.
Hudak says Ontario can't afford to keep the high-spending Liberals in power, especially when they are propped up by the NDP, and voters will see a very clear difference with the Conservatives.
"It’s a very clear choice between the other two parties that just want government to get bigger and more expensive and raise your taxes," said Hudak.
"We’re laying out a plan to make Ontario best for job creation, to balance our books, and have high quality public services, so if an election comes, you may not agree with all of our ideas, might not like all of our policies, but at least you can respect you know where the PC party stands."
Both opposition parties have been fuming that McGuinty shut down the legislature and all its committees just hours before public hearings were to start into the Liberal government's decisions to cancel gas plants in Oakville and Mississauga at a cost to taxpayers of at least $230 million.
However, other than vague promises to give people more of a say in locating energy projects, the seven men and women running to replace McGuinty have said little about the cancelled plants, which the Tories and NDP say could cost over $1 billion.
The would-be premiers face two critical dates in the coming weeks: about 1,700 delegates who can vote directly for the new leader will be selected at riding association meetings across Ontario the weekend of Jan. 12-13, and the leadership convention itself Jan. 25-27 at Maple Leaf Gardens.
As the Liberal leadership candidates ponder their future in the premier's office, they might be a little concerned by an online survey by Angus Reid Nov. 25-Dec. 3 that found McGuinty was the least popular premier in the country with a 23 per cent approval rating. That compared to 67 per cent for Saskatchewan's Brad Wall.