Former Rep. Rob Portman (R) said Monday that he has more than $6 million in cash on hand for his Senate campaign in the Buckeye State.

Portman, who headed the Office of Management and Budget and served as U.S. trade representative during George W. Bush’s administration, said in a campaign release that he raised more than $1.4 million in the final three months of 2009.

Republican officials in Washington, D.C., and Ohio prefer Portman in a GOP primary that also includes wealthy car dealer Tom Ganley, who raised $1.5 million in last year’s fourth quarter and has $1.3 million in cash on hand. Ganley’s campaign hasn’t said how much of that take came from the candidate’s pockets.

Portman raised significantly more than Ohio Lt. Gov. Lee Fisher (D), whose campaign said Jan. 13 that it raised more than $780,000. Ohio Secretary of State Jennifer Brunner, who’s competing with Fisher for the Democratic nomination but struggling to raise money, has not yet released fourth-quarter fundraising figures.

Portman and Fisher have been sparring as if they expect to become the nominees. In his fundraising release, Portman criticized Fisher’s record as Ohio’s lieutenant governor and “jobs czar.— Fisher has described Portman as a Washington insider.

All four candidates must file detailed campaign finance reports by Jan. 31. They’re seeking the seat of retiring Sen. George Voinovich (R).