George Smitherman's oft-rumoured bid to become Toronto mayor is coming to fruition.

According to reports Sunday night, Smitherman will leave his post in Dalton McGuinty's provincial government and begin a campaign to lead Canada's largest city.

The election for mayor will come next November but it's expected that a formal announcement from Smitherman will come on Monday.

Smitherman has been one of McGuinty's highest-ranking cabinet ministers in the past few years and had sat as both deputy premier and the province's energy minister.

Toronto Coun. Paul Ainslie trumpeted the news on the social networking site Twitter Sunday night, writing: "George Smitherman resigns to rund (sic) for Mayor of TO!"

Smitherman told The Globe and Mail on Sunday that the time is right for a change.

"I've been thinking about it for a long, long time," Smitherman said. "In my mind, in my heart, I'm settled on doing it."

Smitherman's desire to run for mayor of Toronto has been one of the worst-kept secrets in provincial politics over the past year.

After denying the reports for months, Smitherman said in September that he would consider a run for the job.

During the summer municipal strike in Toronto, Smitherman - who is the MPP for Toronto Centre - was filmed picking up garbage alongside long-time political foe John Tory.

Tory, the former leader of the provincial Conservatives, has also been considered a contender for the mayor's chair.

The race for the position heated up earlier this fall when David Miller announced he would not run for another term.

Miller's standing with voters took a beating during the summer municipal strike, which resulted in massive mounds of stinking garbage piling up around the city.

The final blow came earlier this fall when the true cost of the so-called sick day bank was revealed to be higher than many had expected. The sick day bank was considered the key issue during the strike.

Meanwhile, The Canadian Press reports that Gerry Phillips will take over the energy portfolio at Queen's Park.

The bid won't be Smitherman's first foray into politics at the municipal level. He once ran the mayoral campaigns for Barbara Hall.

Some analysts believe that Smitherman's announcement was hastened by a recent dust-up at Queen's Park, in which Smitherman was confronted about his dealings with the Samsung Group.

Smitherman had been courting the South Korean industrial giant for a deal to build a multi-billion dollar wind turbine facility in the province.

However, McGuinty stalled the agreement amid concern that too much provincial cash would be used to subsidize the deal.

During one caucus meeting, Smitherman was reportedly attacked by his colleagues about the deal's specifics.