When speaking with reporters at Queen’s Park on Tuesday morning, Duncan said that any prospective candidate vying for the leadership is aware that the premier’s job is a demanding one.
"The key factor for me is the time," Duncan said.
While Duncan said he has not yet reached a final decision, he has the backing of those closest to him.
"I can tell you if I choose to go forward, my family would be supportive of that," he said.
The Ontario Liberal Party will hold a leadership convention in January to determine a successor to departing Premier Dalton McGuinty, who has led the party since 1996.
McGuinty, 57, made a surprise announcement eight days ago that he was stepping down and also that he was proroguing the provincial legislature.
Support for prorogation
Duncan told reporters Tuesday that he supported the premier’s decision to prorogue the house and he believes that the government will still be productive while the legislature is on hiatus.
"I think some work can get done, I know a lot of people don’t agree with me on that, but I do support the decision to do it," he said.
The Tories lashed out at Duncan for supporting McGuinty's move to shut down all legislative business, including committees.
"Prorogation is a very, very serious thing and at a time when Ontario is literally on fire from a fiscal perspective, he's got no business making an irresponsible statement like that," said PC critic Peter Shurman.
The New Democrats said people are outraged by McGuinty's move to prorogue the legislature, which they said demeans all politicians.
"People expect us to be here in the legislature addressing the big questions, so when people see that in fact the legislature is shut down, it makes us look non-credible," said NDP critic Peter Tabuns.
"When they see this, it disgusts them frankly."
The opposition parties say the only reason McGuinty prorogued was to shut down scheduled committee hearings into the Liberals' decision to cancel generating stations in Oakville and Mississauga, at a cost to taxpayers of at least $230 million.
The Tories and NDP estimate the actual cost of cancelling the gas plants is closer to $1 billion, and say the money was spent to save Liberal seats in last fall's election.