Updated: 4:43 p.m.

Sen. Jim Bunning (R-Ky.) announced Monday afternoon that he is retiring in 2010, after months of reiterating his commitment to running for re-election and publicly feuding with leaders in his own party, whom he accused of sabotaging his campaign.

Bunning’s move eliminates a political headache for the Republicans and paves the way for Kentucky Secretary of State Trey Grayson to secure the GOP nomination in the open-seat race.

The Hall of Fame pitcher blamed his fellow Republicans for essentially forcing him into retirement, and alluded to the fact that he is not the most popular Member on Capitol Hill, saying that he was more interested in casting the right vote on an issue, as opposed to voting to earn an invitation to a “D.C. cocktail party.—

“To win a general election, a candidate has to be able to raise millions of dollars to get the message out to voters,— Bunning said in a statement. “Over the past year, some of the leaders of the Republican Party in the Senate have done everything in their power to dry up my fundraising. The simple fact is that I have not raised the funds necessary to run an effective campaign for the U.S. Senate. For this reason, I will not be a candidate for re-election in 2010.—

Bunning raised a little more than $300,000 in the second quarter and ended June with $596,000 in cash on hand.

Grayson, who has already begun a Senate exploratory effort, is likely to be the Republican standard-bearer in the open-seat race.

Grayson was the preferred candidate of many Republican insiders, who have viewed Bunning as a political dead man walking based on his poll numbers and lackluster fundraising, among other things.