William Daley, a former U.S. commerce secretary and the brother of Chicago's mayor, says he does not plan to run for governor of Illinois.

Daley had been considered a possible favorite for the Democratic nomination. 

In an interview with the Chicago Sun-Times, Daley said that while he had been overwhelmed by the support for his possible candidacy, he felt he needed a break from politics. He served last year as campaign manager in former Vice President Al Gore's quest for the White House. 

"It's just not the right time," Daley, 53, told the newspaper. "It would be a great honor to serve as governor of Illinois. But at this stage in my life, I have to do what is right for me and my family." 

Daley and his wife, Loretta, recently announced their separation. 

Although he had not formally announced his intentions in the race to succeed Republican Gov. George Ryan, Daley had received strong support from leading Illinois Democrats, including state chairman Michael Madigan and U.S. Sen. Richard J. Durbin. 

Daley, the brother of Mayor Richard M. Daley, also said he did not want to make the financial sacrifice running for office would entail. He recently became vice chairman and senior managing director of Evercore Partners, a New York investment banking firm. 

Daley's withdrawal turns the Democratic gubernatorial race back into a free-for-all. The current field includes former Illinois Attorney General Roland W. Burris, former Chicago Schools Supt. Paul Vallas and U.S. Rep. Rod Blagojevich. 

With apparent Republican disarray after Ryan's decision not to seek a second term, Democrats have seen the upcoming election as their best chance in years of recapturing the governor's office. No Democrat has served as Illinois governor since 1977.