The execution of a convicted murderer has been delayed in the United States after doctors refused to participate because of ethical objections.
Morales would be the 14th inmate to be executed in California since 1977
Michael Morales was set to become the first inmate to be put to death by lethal injection in California under a procedure that aims to minimise pain.
Morales, 46, was convicted of the rape and murder of a teenage girl in 1981.
Prison officials have rescheduled the execution, saying they will use a different type of lethal injection.
Officials at San Quentin prison announced the postponement of the execution more than two hours after it had been due to take place, citing serious differences of opinion with two anaesthesiologists.
The two court-appointed doctors withdrew, citing concerns over a last-minute ruling by a judge.
Ninth Circuit Court of Appeals judge Jeremy Fogel on Monday ordered them to intervene in the event that Morales woke up or appeared to be in pain.
"Any such intervention would be medically unethical. As a result, we have withdrawn from participation in this current process... What is being asked of us is ethically unacceptable," the doctors said in a statement.
US METHODS OF EXECUTION
Lethal injection: Authorised in 37 states
Electrocution: In 10 states (sole method in Nebraska)
Gas chamber: In five states (all of which have lethal injection as alternative)
Hanging: Only in New Hampshire and Washington
Firing squad: In Idaho and Oklahoma
Prison officials have rescheduled the execution for 1930 (0330 GMT on Wednesday).
They now plan to use a fatal dose of barbiturate - a sedative - instead of the three-drug cocktail typically used for executions.
The judge had given the state that option, but officials had previously rejected it because it could take up to 45 minutes to kill the inmate instead of usual eight to 10 minutes.
The "death warrant" expires at 2359 local time (0759 GMT Wednesday). If Morales is not executed by then, a judge will have up to 60 days to set another execution date.
Clemency plea denied
The decision to have anaesthesiologists present was made after lawyers for Morales had successfully argued that he would suffer extreme pain because of the mix of drugs in the three-part injection.
They had said that the lethal cocktail violated the Eighth Amendment prohibition on cruel and unusual punishment.
The American Medical Association, the American Society of Anesthesiologists and the California Medical Association have opposed anaesthesiologists' participation as unethical.
Morales was sentenced to death for raping and killing 17-year-old Terri Winchell in 1981.
He admitted the crime, but claimed he was high on drugs and alcohol.
On Monday, Morales was denied his last-minute clemency plea by California's governor.
It was the second time Arnold Schwarzenegger had declined his request, citing "the record and totality of circumstances in this case".