Political warfare in Lake County escalated this week as supporters of the embattled sheriff launched an effort to recall his main antagonist on the Board of Supervisors.

Organizers served Kelseyville-area Supervisor Rob Brown with a notice that they will try to recall him, citing his "rude and overbearing" personality.

"Your behavior encourages others to behave similarly, creating an unlivable atmosphere that detracts from the beauty, and enjoyment of our county," they wrote on the recall petition.

Brown has been a leading critic of Sheriff Frank Rivero, saying the county's top lawman has behaved in an arrogant manner that has alienated the public and sparked feuds with other law enforcement agencies and elected officials. Brown co-sponsored a motion of no-confidence in the sheriff, which was passed unanimously by supervisors earlier this year, and he has openly helped organizers of a recall effort against Rivero.

"I tend to be pretty vocal about things," Brown said, conceding that he is a pugnacious figure in county politics. "I'm not going to walk down the middle of the road."

Recall organizers deny the campaign is revenge for Brown's outspoken stand against Rivero, though they say that is a continuation of Brown's aggressive leadership style.

"We're tired of the way he treats people; we're tired of the way he talks to people," said retired Clearlake contractor Joel Moore, who is leading the recall effort, despite not living in Brown's district.

Moore tried to file the formal paperwork on Wednesday with the county Registrar of Voters office, but Registrar Diane Fridley said Thursday there was a technical problem that will require them to refile, delaying the official start of the recall effort.

Organizers notified Brown of their plans May 10. They need the signatures of 1,833 voters in his district to force a special election. Brown's last opponent, musician and writer Joan Moss, polled just 986 votes to Brown's 2,145 in the 2012 election, which gave him a fourth term on the board.

The effort to recall Rivero, meanwhile, is now in its third week of collecting signatures. Several candidates have lined up to challenge the sheriff should his critics collect signatures from at least 7,026 county voters by Aug. 15.

So far, they have collected about 3,500 signatures, Brown said. They hope to get over the threshold by June 17, in time to qualify the matter for the Nov. 5 ballot. If they miss that deadline, critics would still have another month to collect signatures, but the recall would be delayed until a later special election.

The dueling recall efforts are the latest battles in an increasingly contentious period in Lake County following the 2010 election. That year, Rivero, then a deputy, unseated longtime Sheriff Rod Mitchell after a series of well-publicized scandals and management problems. He promised to clean up the department and uproot a corrupt "old boy network" in the county.

He quickly locked horns with other officials, however, including newly-elected District Attorney Don Anderson, and with the supervisors, sparring over a series of funding issues. Anderson later added Rivero to a list of officers whose court testimony might be compromised, saying he lied to investigators looking into a 2008 shooting incident. Rivero has vehemently denied the charge, calling it a political effort to smear him.

The turmoil led the supervisors to pass the non-binding no-confidence measure in March, calling on Rivero to resign. Rivero has refused and accused his critics, particularly Brown, of being part of an endemic culture of corruption.

The Sheriff's Office has been locked in a battle with other law enforcement agencies, meanwhile, over access to a database containing sensitive personal records on suspects and details of investigations. Rivero cut off most outside access to his database last month, saying outside agencies had abused their privileges and compromised private information.