Question to appear on November ballot after more than 500,000 people signed up to back the proposal.

Voters in California will have the chance to cast ballots on a referendum on ending the death penalty in November.

The “Savings, Accountability and Full Enforcement for California Act,” or SAFE California Act, garnered enough support signatures, and will be considered on November 6, when Americans head to the polls for general elections, Debra Bowen California’s Secretary of State said on Monday.

Supporters collected more than the 504,760 valid signatures needed to place the measure on the ballot.

If the measure is approved, the 725 California inmates now on Death Row will have their sentences converted to life in prison without the possibility of parole. It would also make life without parole the harshest penalty prosecutors can

seek.

Backers of the measure said abolishing the death penalty would save the state millions of dollars through layoffs of prosecutors and defence lawyers who handle death penalty cases, as well as savings from not having to maintain the nation’s largest death row at San Quentin Prison.

If the measure passes, $100m in purported savings from abolishing the death penalty would be used over three years to investigate unsolved murders and rapes.

“Our system is broken, expensive and it always will carry the grave risk of a mistake,” said Jeanne Woodford, the former warden of San Quentin prison, who is now an anti-death penalty advocate and an official supporter of the measure.

When the death penalty was reinstated in 1978, “we did not have an alternative sentence that would keep convicted killers behind bars forever. We certainly did not know that we would spend $4bn on 13 executions,” she said in a statement.

If passed, California would become the 18th US state to eliminate the death penalty.

The measure will also require most inmates sentenced to life without parole to find jobs within prisons. Most death row inmates do not hold prison jobs for security reasons.

Cost-saving measure

Although California is one of 35 states that authorise the death penalty, the state has not put anyone to death since 2006. Since reinstating the death penalty in 1978, it has executed 13 inmates.

A 2009 study conducted by a senior federal judge and law school professor concluded that the state was spending about $184m a year to maintain Death Row and the death penalty system.

Supporters of the proposition, such as the American Civil Liberties Union, are portraying it as a cost-savings measure in a time of political austerity.

They count several prominent conservatives and prosecutors, including the author of the 1978 measure adopting the death penalty, as supporters, and argue that too few executions have been carried out at too great a cost.

Opponents of the measure, such as former Sacramento US Attorney McGregor Scott, however argue that lawyers filing “frivolous appeals” are the problem, not the death penalty law.

“On behalf of crime victims and their loved ones who have suffered at the hands of California’s most violent criminals, we are disappointed that the ACLU and their allies would seek to score political points in their continued efforts to override the will of the people and repeal the death penalty,” said Scott, who is chairman of the Californians for Justice and Public Safety, a coalition of law enforcement officials, crime victims and others formed to oppose the measure.

The Criminal Justice Legal Foundation, meanwhile, remains one the biggest backers of the death penalty in the state and opposes the latest attempt to abolish it in California.

The foundation on Thursday filed a lawsuit seeking the immediate resumption of executions in California.