Gov. Jerry Brown has ordered prison officials to consider a single-drug method of executing condemned inmates as the state appeals a court order that has blocked California from carrying out the death penalty.

Mention of the directive came in a notice of appeal filed Thursday by Atty. Gen. Kamala D. Harris seeking to counter a February ruling that halted a revised three-drug lethal injection method. The filing came just three days after certification of a November ballot measure that would offer voters the chance to repeal California’s death penalty.

The legal filing said the state would reevaluate its position in favor of the three-drug method if “the drugs needed to implement the protocol have, in fact, become unavailable.” The U.S. maker of one of the drugs has stopped manufacturing it.

“In the meantime, under the governor’s direction, the California Department of Corrections and Rehabilitation will also begin the process of considering alternative regulatory protocols, including a one-drug protocol, for carrying out the death penalty,” the filing said.

A conservative law and order group sued the state last week to force it to implement a single-drug method of execution, a procedure used in nearly two dozen executions in other states.

A federal judge in 2006 halted executions in California after finding that inmates might experience excruciating pain under the state’s three-drug procedure. California then revised its three-drug protocol, but a Marin County judge ruled in February that the state should have considered a single-drug method.

Death penalty opponents have long complained that the three-drug method could expose inmates to intense suffering, violating the Constitution’s prohibition of “cruel and unusual punishment.” During a federal trial, lawyers for a death row inmate presented evidence that inmates executed in California were not properly anesthetized by the first drug, which was followed by two drugs to paralyze them and stop their heart.

At least three states are executing inmates with a single large dose of pentobarbital, said Kent Scheidegger, legal director of the California Criminal Justice Legal Foundation, the group that sued the state.

Fears that a single drug would take too long to bring on death have not been borne out, although one inmate executed by pentobarbital reportedly shook violently before dying, Scheidegger said.

“It’s about time” the state appealed the Marin County ruling, said Scheidegger, who faulted the Brown administration for not seeking a stay of the decision.

Harris’ aides referred questions about the appeal to Brown’s office, which released a one-sentence statement from the governor: “My administration is working to ensure that California’s laws on capital punishment are upheld.”

maura.dolan@latimes.com