A former political opponent said Wednesday he may launch a recall against San Mateo County Supervisor Don Horsley for breaking a campaign promise to not accept a salary because he draws $215,000 a year in pension pay.

Although Horsley didn't collect the annual supervisor's salary of $120,000 his first two years, the former county sheriff announced last month he now will take the pay, citing financial need.

Michael Stogner, who ran against Horsley for the District 3 supervisor's job in 2010, officially put Horsley on notice in an email Wednesday to rescind his decision to take the salary in the next 30 days or face a recall.

"The man was once in charge of our law enforcement organization. He's a sworn officer. He knows what an oath is, he knows what a promise is," Stogner said in a phone interview.

Horsley said he made the no-salary pledge when the county was facing a triple-digit deficit, but today the economic outlook has improved. In November, voters also approved a half-cent sales tax that will funnel a projected $60 million into county coffers annually for each of the next 10 years.

"Point out to me any other public official in California that doesn't take a salary. It's discriminatory to say I should not take a salary like all my colleagues do," Horsley said in a phone interview Wednesday. "I think I've honored that pledge enough; it was three years ago, when the county was in a different position and the economy was in a different position."

A recall would be senseless, Horsley added.

"Recalls are usually for incompetence or some criminal act," he said. "I think I've been extremely competent. I've done a good job. I haven't done any criminal act."

Since voters also approved a ballot measure in November that replaces a countywide system of electing supervisors with a district system, Stogner said he will need considerably fewer signatures to get a recall on the ballot. Deputy County Counsel Glenn Levy said Wednesday he didn't know whether that would be the case since Horsley was elected through the countywide system.

Stogner also tried to recall Sheriff Greg Munks in 2007 after the sheriff was caught in a sting operation while visiting a Las Vegas brothel, but he dropped that effort.

On Tuesday night, Horsley was selected by his supervisor colleagues to serve this year as board president and Dave Pine was picked to be the vice president. During the meeting, Horsley said reducing gun violence would be among his top priorities for the coming year, possibly through a gun-buyback program and more extensive background checks of gun buyers in the county.

Email Bonnie Eslinger at beslinger@dailynewsgroup.com; follow her at twitter.com/bonnieeslinger.