SAN FRANCISCO (Reuters) – California in November will vote on whether to raise a four-decade-old cap on medical malpractice awards to $1.1 million, from $250,000, officials said on Thursday, likely ensuring a bitter and costly fight between lawyers backing the measure and doctors who oppose it.

Representatives of patients have tried for at least 20 years to persuade the state to raise the limit on pain-and-suffering awards, which was set in the 1970s and is not indexed to inflation. Opponents say a higher cap will raise healthcare costs and choke off access to care.

Consumer advocates successfully collected hundreds of thousands of signatures in support of placing the measure on the ballot, according to the California Secretary of State, which approved Initiative #13-0016 for the ballot.

"Patient safety laws have not been modernized for 38 years and as a result dangerous doctors are not deterred and families victimized by medical negligence cannot get access to justice," said Jamie Court, president of the non-profit Consumer Watchdog, a co-sponsor of the initiative.

The initiative would also require random drug testing of doctors in the wake of growing concern about over-prescription of addictive pain medications, including among doctors, Court said.

Doctors would also have to check a statewide drug history database before prescribing certain drugs to patients who may be collecting prescriptions from different doctors, Court said.

Staunch opposition has mounted from the California Medical Association and other representatives of doctors, as well as medical providers such as clinics and hospitals, making proposed changes difficult to enact.

In March, California Medical Association president Richard Thorp said lifting the existing $250,000 cap for medical malpractice awards would make health care costs rise even further, as doctors would be forced to spend more on malpractice insurance.

Opponents of the measure, including insurance companies and medical groups, have raised more than $33 million in 2014, far outpacing the less than $700,000 raised by proponents, campaign finance records showed, according to the Los Angeles Times.

A bill introduced in February that would have raised the limit under the Medical Injury Compensation Reform Act, or MICRA, to $500,000, failed to gain traction.

(Reporting by Jennifer Chaussee in San Francisco; Writing by Eric M. Johnson)