Ontario Premier Dalton McGuinty has confirmed that long-time cabinet minister Kathleen Wynne will take a run at the provincial Liberal Party leadership, making the announcement just after it was revealed she’d resigned her cabinet post.

Calling Wynne “a very strong candidate,” McGuinty shared the news with reporters in London, Ont., on Friday. He had previously said that any cabinet minister who wished to run for the position would have to step down from his or her portfolio.

"I want to thank Kathleen Wynne for serving Ontarians in a number of portfolios and for her commitment to public service,” he said in a release. The memo also announced a cabinet reshuffle: Bob Chiarelli, currently Minister of Transportation and Minister of Infrastructure, will also take on the Municipal Affairs and Housing portfolio, and Energy Minister Chris Bentley will also take Aboriginal affairs.

“I thank Minister Chiarelli and Minister Bentley for taking on these added responsibilities,” McGuinty said.

The ministers are to be sworn into their new portfolios next week.

Earlier Friday, Wynne had announced she is stepping down as minister of municipal affairs and housing, bolstering rumours she would become the first Liberal to officially declare a leadership bid. Wynne has scheduled a news conference in her Don Valley West riding for Monday morning, when she's likely to make the announcement herself.

A statement announcing her resignation pointed out Wynne has also served as minister of transportation and minister of education during her tenure in cabinet. She will maintain her MPP role.

If selected as Liberal leader, Wynne would become both the first openly gay premier, and first female premier, in Ontario. A former school board trustee, she was first elected to the Legislature in 2003 when McGuinty’s Liberals took office. She is 59 years old and has three grown children.

McGuinty surprised Ontarians on Oct. 15 when he announced his resignation as party leader and prorogued the provincial legislature, arguing that the climate at Queen's Park had become toxic. He said MPPs needed time to step away and regroup.

The legislature will not resume until the Ontario Liberal Party has chosen a successor, and that person calls MPPs back to work. A leadership convention is scheduled for Jan. 25-27 in downtown Toronto.

Though no one has officially declared their intention to run, former Liberal cabinet minister Sandra Pupatello has acknowledged she is considering a bid. Glen Murray, the MPP for Toronto Centre and the former mayor of Winnipeg, is also considered a strong possibility, as is Gerard Kennedy, a former MP and MPP who lost the leadership to McGuinty by just 140 votes in 1996.

Eric Hoskins, the children and youth services minister who started War Child Canada with his wife, is holding his cards close to his chest.

"I'm giving it serious consideration, but I have not yet made a decision," he told The Canadian Press on Friday, adding he has "nothing but the greatest respect" for the "wise" and "experienced" Wynne, whose riding is next door to his own.

A number of Liberals who were widely considered to be contenders to replace McGuinty, however, have announced their intention not to run. Finance Minister Dwight Duncan this week said he wasn’t interested, as have former Liberal cabinet minister and Toronto mayoral candidate George Smitherman, Energy Minister Chris Bentley, Education Minister Laurel Broten and Economic Development Minister Brad Duguid.

During a recent news conference, McGuinty was asked whether he was concerned that high-profile cabinet ministers, such as Duncan, appeared to have little interest in the party’s top job. McGuinty replied that it was a personal decision and he wasn’t worried.

That said, his party has been widely criticized for closing down the legislature in the midst of scandals over cancelled gas plants in hotly contested Liberal ridings and mismanagement at the province’s air ambulance service.

"Early days yet," he said. "I know that we're going to have a very hotly contested race.”

With files from The Canadian Press