PORTLAND, Ore. — The Oregon agency that certifies police officers says the sheriff of the state’s most populous county — a member of the force for nearly half his 70 years — has to go back to basic training.

Multnomah County Sheriff Bob Skipper will become a police cadet next month — possibly the oldest in state history — unless he and other county officials persuade the Department of Public Safety Standards and Training to reconsider.

“My job is not to write citations — I am the CEO,” Skipper told The Oregonian newspaper as his office prepares for a $9.4 million budget cut and large-scale layoffs.

“I’m having to back myself out of the middle of all this and say, ‘I can’t deal with this right now. I have to go off and learn to be a patrolman.”’

Skipper returned to the job after 13 years of retirement when Sheriff Bernie Giusto stepped down amid an ethics scandal. His time away from the job meant that he had to seek a waiver to avoid going through the four-month basic training for new recruits, even though he has spent 34 years in the sheriff’s office, five as sheriff.

The standards and training department can make exceptions but did not in Skipper’s case. Multnomah County Chairman Ted Wheeler and District Attorney Michael Schrunk have written letters appealing to the agency to reconsider.

Eriks Gabliks, deputy director for the training agency, said the law is clear.

“Anyone out over five years has to go back to basics unless they remained current somehow in law enforcement,” Gabliks said.