George Smitherman, the province's former deputy premier, has officially begun his campaign to run for mayor of Toronto.

Smitherman filed his nomination papers Friday morning, before launching his campaign with a photo op of him skating at Nathan Phillips Square.

He wouldn't unveil any policies, saying he first wants to go and visit the city's 44 wards.

"I think I owe it to the people of Toronto to get out into the neighbourhoods and hear from them what the key challenges are," he said, adding after that, he will form an agenda for action.

Smitherman has previously indicated he will make job creation in the city a key part of his campaign and administration, should he win.

A former Liberal MPP for Toronto Centre, Smitherman resigned as a cabinet minister last fall, sparking speculation that he was planning a mayoral run.

So far, 13 candidates have signed up to run in the city's next mayoral election, to be held on Oct. 25. Among them is Rocco Rossi, former director of the federal Liberal party and Coun. Georgio Mammoliti.

Coun. Joe Pantalone, a council veteran, has indicated he will join the race next week.

Couns. Adam Giambrone, Shelley Carroll and Rob Ford have indicated they are considering a run.

John Tory, the former leader of the Ontario Progressive Conservatives who finished second in Toronto's last mayoral race, said Thursday he will not make another run for the position. Instead, Tory will keep his position as a talk-radio host and will run the Toronto City Summit Alliance.

David Miller said in the fall he will not seek re-election.

With a report from CTV Toronto's Alicia Markson and files from The Canadian Press