In a surprise move, Ontario Premier Dalton McGuinty announced Monday he is stepping down and proroguing the legislature because his minority government and the opposition have reached an impasse on public sector wage freezes.

“After 16 years as leader of the Ontario Liberal Party, and after nine years as premier, it’s time for renewal. It’s time for the next Liberal premier, it’s time for the next set of Liberal ideas to guide our province forward,” McGuinty said at an urgent meeting of the Liberal caucus, as his wife Terri looked on from the front row.

McGuinty said he has asked the party’s president to convene a leadership convention “at the earliest possible opportunity” and will continue to serve as premier until a new leader is elected.

He also said he will stay on as MPP for Ottawa-South until the next election.

The resignation prompted immediate speculation about whether McGuinty is considering a run for federal Liberal Party leadership.

Pressed for an answer at a Monday night news conference, McGuinty repeatedly said: “I have no plans,” but did not explicitly rule out a federal leadership bid.

However, insiders say McGuinty hasn’t done any polling to gauge the level of support he would get from Liberals across Canada. His wife is also not in favour of another leadership campaign, sources told CTV’s Ottawa Bureau Chief Robert Fife.

McGuinty said he visited Lieut.-Gov. David Onley earlier in the day and asked him to prorogue the legislature. McGuinty said the move is necessary for the Liberal government to negotiate a wage-freeze agreement with the province’s public-sector workers in an effort to eliminate the province’s deficit.

McGuinty blamed the suspension of the legislature on the opposition parties’ unwillingness to support his government’s efforts to secure that wage freeze.

He said he wants to be able to pursue discussions with labour groups, and the opposition, “in a way that is free of the heightened rancour that has sadly too frequently characterized our legislature of late.”

When the House returns, he said, “we will either have negotiated agreements in hand, or a legislative plan supported by the opposition.”

Opposition leaders commended McGuinty for his 22 years of public service, first as an MPP and then as premier, but urged him to reconsider prorogation and putting on hold the work that needs to be done in the legislature.

NDP Leader Andrea Horwath said adjourning the legislature “effectively cancels” hearings on the multi-million dollar cost of cancelling gas plants in Mississauga and Oakville, which triggered a contempt motion against Energy Minister Chris Bentley.

She said the timing of McGuinty’s resignation is “curious.”

Progressive Conservative Leader Tim Hudak said the contempt motion will “die” when the House shuts down, but his party plans to resurrect the issue when the legislature returns.

McGuinty told reporters he’s not leaving because of the gas plant controversy or other troubles dogging the provincial Liberals, including a financial scandal involving the air-ambulance service Ornge.

He said two recent events helped him decide that “it’s time to go”: his daughter’s wedding and the Ontario Liberal Party’s annual general meeting, where he sailed through a confidence vote.

McGuinty said watching his daughter tie the knot made him realize that he wanted to spend more time with his family. Knowing that his party supported him made the decision to leave a lot easier, he said.

“The party is behind me, but my responsibility is to look to the future. And my responsibility is to ensure that we renew our party.”

Interim federal Liberal Leader Bob Rae released a statement Monday praising McGuinty’s years in office, calling him a “global leader in education” for introducing all-day kindergarten in the province and making post-secondary education “more accessible and affordable than ever before.”

Justin Trudeau, who joined the federal Liberal leadership race with much fanfare, also congratulated McGuinty and said now is a “time of reflection” on the premier’s achievements.

Prime Minister Stephen Harper thanked McGuinty for “his contributions to Ontario and to Canada,” saying the two governments have worked together to serve Ontarians.

Politicians outside Ontario, including Alberta Premier Alison Redford, also expressed their surprise at McGuinty’s departure and wished him well.

“Premier McGuinty served the people of Ontario well for sixteen years as a statesman, a fierce defender of his province and a leader in confederation,” Redford said in a statement. “Over the past year I have truly benefited from his views and opinions. I consider Premier McGuinty a valuable colleague as well as a friend.”

McGuinty’s announcement followed just hours after Finance Minister Dwight Duncan read the government’s fall economic update in the Legislature. Duncan said the province’s deficit for the 2012-13 fiscal year is projected to be $14.4 billion, which is about $400 million lower than previously expected.

Duncan emphasized the need for the province to secure a two-year public-sector wage freeze in order to meet the government’s goal of eliminating the deficit by 2017-18.

But Hudak dismissed the document, telling Duncan in the Legislature that it was “an unremarkable, unimaginative and unhelpful embrace of the status quo,” before launching into a speech of promises should the PCs take power.

Horwath told reporters after that she understood the need for a wage freeze, but objected to the government’s threat to enforce the freeze via legislation.

The McGuinty government signalled its intent to get the province’s books back to black in its spring budget, which vowed to reign in salaries, benefits and other compensation for doctors, teachers and other public-sector workers.