TORONTO -- Ontario Premier Kathleen Wynne praised Dalton McGuinty Wednesday as "an unwavering political force" after her predecessor announced his resignation as the member of provincial parliament for Ottawa South.

"He reminded us that government could build us up through investments in education, health care, research and innovation," Wynne said in a statement.

"He steered this province thought a global recession and three general elections."

Word of McGuinty's resignation started leaking late Tuesday, upstaging Wynne's first big accomplishment as premier -- passage of the minority government's budget.

McGuinty issued a statement Wednesday morning saying the end of the legislative session was "an opportune time for me to bring to a close my service to the people" in his riding after nearly 23 years.

"I am proud to have been Ontario's first premier from Ottawa, and proud to have drawn my life's lessons and values from my parents' home in Alta Vista," he said.

"It has been my greatest honour and privilege to follow in my father's footsteps."

Dalton McGuinty Sr. represented Ottawa-South until his death in 1990, when his son successfully ran to replace him.

McGuinty is leaving with the $585-million gas plant scandal tainting his legacy, and amid fresh allegations that top Liberal staff in his office wiped out email accounts to try to cover up the costs of cancelling the energy projects.

His two-page statement makes no mention of his controversial decisions to cancel gas plants in Oakville and Mississauga to save Liberal seats in the 2011 election, when the party was reduced to a minority government after two terms as a majority.

"I leave politics with my idealism intact and a deep sense of gratitude for the opportunity to have served in public life," wrote McGuinty.

Last week, Ontario's information and privacy commissioner reported senior staff in McGuinty's office not only deleted their email accounts in an apparent attempt to cover up the costs of cancelling the gas plants, they also tried to wipe the correspondence from government databases.

McGuinty issued a statement last Friday denying he had ordered staff to destroy government records in violation of the law.

The Ontario Provincial Police launched a criminal probe into a complaint from the Progressive Conservatives about the missing emails, which the government was ordered to produce by the Speaker of the legislature.

The Tories say they want McGuinty to appear again at the justice committee hearings into the gas plants to answer questions about the mass deletions of emails.

The Ontario Liberal Party has scheduled a nomination meeting for June 20 in Ottawa South to find a candidate to replace McGuinty in a byelection.

Wynne has six months to call the vote, but is expected to call it later this summer because she faces an Aug. 15 deadline to call byelections in Windsor and London to replace former finance minister Dwight Duncan and former energy minister Chris Bentley. Both men quit after Wynne was sworn in as premier in February.