Dalton McGuinty won't seek the federal Liberal leadership.

The Ontario premier told The Canadian Press he's decided it's time to ``take on challenges outside of politics.''

McGuinty shocked the nation last week by announcing his intention to resign as premier; he refused at that time to rule out a leap to the federal stage. But after a week of contemplation and mounting pressure from federal Liberals eager to see a heavyweight rival to prohibitive front-runner Justin Trudeau, McGuinty says he's concluded the timing just isn't right for him.

He's promised to stay on as premier until a successor is chosen the weekend of Jan. 25, leaving little time to campaign for the federal race, which is already well underway and culminates April 14.

Moreover, after 16 years at the helm of the Ontario Liberals, nine of them as premier, the 57-year-old McGuinty says he's not prepared to commit the next 10 years of his life to rebuilding the federal Liberals, who were reduced to a third party rump in the 2011 election.

(The Canadian Press)