Five Liberal MPPs have departed Queen's Park in recent months, leaving the minority government with just 48 seats in the legislature.
The Progressive Conservatives currently have 36 seats, while the New Democrats have 18.
Two of the vacant ridings are in the Toronto area, while the remaining three are in Windsor, London and Ottawa. The byelections will take place on Aug. 1.
While the Liberals have been reeling from an ongoing controversy over the costly cancellation of a pair of power plants, the Progressive Conservatives appeared pessimistic about their chances in the upcoming byelections.
"We have to remember that these five byelections are being held in ridings that the Liberals have held for quite some time, so they do have a strategic infrastructure advantage in terms of their campaign team," said PC critic Lisa MacLeod.
Bryan Evans, an associate professor of politics at Toronto's Ryerson University, said it is unusual to see so many byelections held at the same time, especially if voters are keen to punish the sitting government.
"Byelections are an opportunity to punish a government but not defeat it, and come the general election, vote for that government if it is deemed better than the alternatives," he said in an interview with The Canadian Press.
Parties lining up candidates
The Liberals have already selected candidates to run in the ridings of Windsor-Tecumseh and Ottawa-South.
In the riding of London West, the Liberals are expected to acclaim Ken Coran, the recently retired head of the Ontario Secondary School Teachers' Federation, as their candidate.
Coran had led the OSSTF during a period in which it was at war with the governing Liberals over legislation they used to impose contracts on public-sector teachers. He once boasted about helping to defeat the Liberal candidate in a byelection in Waterloo last year.
New Democrat MPP Cheri DiNovo said the government shouldn’t count on seeing votes pour in for Coran, given that they won’t approve of a former union leader “turning” on the people he once represented.
"I think it's somewhat shameful that you have a union leader running for an anti-union party, a union leader who is out protesting Bill 115 turns around and runs for the government that brought it in," said DiNovo.
In Toronto, Coun. Peter Milczyn was acclaimed as the Liberal candidate in the riding of Etobicoke-Lakeshore.
The Progressive Conservative website lists candidates for all five of the ridings where byelections are set to be held.
The New Democrats have selected candidates for the Windsor and London ridings, but have yet to hold nomination meetings in the remaining three ridings where seats are vacant.
The forthcoming byelections will be the first to occur since Wynne became premier earlier this year.
Wynne won the leadership contest that was triggered when former premier Dalton McGuinty announced last fall that he would step down after serving more than a decade as the leader of the Ontario Liberals.
McGuinty is one of the five Liberal MPPs to depart Queen's Park this year, along with Dwight Duncan, Chris Bentley, Laurel Broten and Margarett Best.