Republican Ken Cuccinelli II, Virginia’s outspoken attorney general who has drawn national support from the tea party movement, confirmed Thursday that he will run for governor in 2013.

Cuccinelli’s candidacy sets up a potentially contentious — and expensive — primary fight against Lt. Gov. Bill Bolling (R), a presumptive gubernatorial candidate.

“I hope you have known me long enough to know that I do this out of my love for our commonwealth and to further the principles on which this country was founded,” Cuccinelli wrote in an e-mail to his staff late Thursday. “I feel that two years from now, I can best serve the people of Virginia from the governor’s office.”

Cuccinelli said he did not plan to make his candidacy official until the spring but moved up his announcement after The Washington Post on Wednesday reported his plans. But Bolling said that Cuccinelli’s decision was rooted in “his own personal ambition.”

Three years ago, Bolling and then-Attorney General Robert F. McDonnell (R) hatched a plan: McDonnell would run unopposed for the GOP nomination for governor, and four years later McDonnell would back Bolling for the state’s top job.

Governor-elect Bob McDonnell, Attorney General-elect Ken Cuccinelli and Lt. Governor-elect Bill Bolling await their swearing in ceremony in January 2010. Cuccinelli’s plan for a ’13 governor run puts him on a collision course with Bolling. (TRACY A WOODWARD/WASHINGTON POST)

Now, just weeks after Republicans won complete control of Richmond, the party is bracing for a potential split ahead of the 2013 election. Republicans on Thursday played down the possibility of a rift in the party, but already some were taking sides.

David O’Kelly, who sits on the State Central Committee, the state GOP’s governing board, called both Bolling and Cuccinelli “good guys,” but he said that he had agreed to support the lieutenant governor because he would better address economic problems. “I’m sticking with Bill all the way through,” he said.

Gary C. Byler, a longtime Republican activist, praised Bolling for stepping aside in 2008 but said that alone should not determine who the next governor will be. Byler said he plans to support Cuccinelli, an “intellectual firebrand,” if only those two run.

“While people appreciate Bill Bolling deferring to Bob McDonnell . . . the governor of the commonwealth is too important to be determined by such niceties,” Byler said.

Cuccinelli, who flew to New York on Thursday to prepare for his role as a questioner in Saturday’s Republican presidential debate, declined to comment, but he issued a statement to the media confirming that he is running. He said he will not resign to campaign for governor, as has been the general practice of his predecessors.

Bolling, a social and fiscal conservative who has campaigned on kitchen-table issues, such as transportation and higher education, has the endorsement of McDonnell, the state’s popular governor, who is barred from running for a second consecutive term.

“Bill is a trusted adviser and a close, personal friend,” McDonnell said in a statement Thursday.

Some political observers speculated that Bolling might drop out of the race and run for reelection or for another post, but he rebuffed that speculation in a harsh statement from Florida, where he is attending a gathering of lieutenant governors.

Bolling said he is “very disappointed” that Cuccinelli decided to join the race after repeatedly saying he would run for reelection. “Unfortunately, he has now decided to put his own personal ambition ahead of the best interests of the commonwealth and the Republican Party,” Bolling said.

Hundreds of Republican activists are expected to gather at their annual retreat at the posh Homestead resort in the western part of the state this weekend. Some say they are interested in revisiting a decision the party made to hold a primary rather than a convention to select their nominee for governor. Bolling supported a primary, which could favor him because it would be open to all voters. Cuccinelli backed a convention, where he would probably be more successful because the nominee would be selected by party insiders.

Several Democrats have expressed an interest in statewide office, but only former Democratic National Committee chairman and businessman Terence R. McAuliffe has told supporters he will run for governor.