Will Tim Cahill be the Bay State's Great Independent Hope?

State Treasurer Timothy P. Cahill plans to announce today that he will challenge Governor Deval Patrick as an independent candidate in next year’s governor’s race, according to several people aware of his plans.

Cahill, who dropped out of the Democratic Party this summer after becoming disillusioned with its direction, has scheduled a late-morning news conference to make his decision public. He intends to kick off the campaign at a fund-raiser at the Adams Inn in Quincy, his hometown.

Cahill will compete against Republicans Charles D. Baker, a former executive at Harvard Pilgrim Health Care, and possibly convenience store magnate Christy Mihos. Mihos is seriously considering switching gears to run for the Senate seat of Edward M. Kennedy, according to an adviser.

Cahill, a longtime Democrat who has served as treasurer since 2003, would not comment on his plans yesterday.

But he has told supporters he feels frustrated that the state cannot function within its budget and continually asks taxpayers for more money.

With his experience at the local, county, and state levels, Cahill believes, he is the most qualified to run the state at a time of financial difficulty, supporters said.

UPDATE: Please be sure to join us this Wednesday night at 8:00pm EST on The Notes on Blog Talk Radio; our guest will be Frank Conte of the Beacon Hill Institute. Plus, more from Boston Magazine and the Herald.

SECOND UPDATE: More from WBUR, Boston Globe, AP and Joan Vennochi.