The Professional Firefighters Union has told members who take emergency calls not to give CPR instructions to 111 callers.
The Professional Firefighters Union says Fire and Emergency staff were sent an email with guidelines for instructing 111 callers in cardiopulmonary resuscitation, if St John staff were not available.
Auckland union secretary John Waldow said its members were horrified when the CPR guidelines were sprung on them.
Mr Waldow said communications staff had not received proper training in telling others how to perform the lifesaving technique, and they had concerns about what would happen if something went wrong.
"Worst case example there would be an inquiry as to why somebody died and it came out someone was receiving instructions over the telephone and those tapes were accessed and they missed something, the question then would be are they liable, in addition to the guilt that would go along with it," he said.
He added it also was not known what support staff would receive if the caller's CPR attempt failed.
St John communications staff all hold an international qualification in giving CPR and defibrillator instruction.
Mr Waldow said the guidelines were sent to staff on 21 December, and were rescinded two days later.
The Fire and Emergency service has denied claims that its call operators were directed to give instructions for CPR over the phone during 111 emergency calls.
Spokesman Carlos Dempsey said the information was just a guideline and had not been rescinded. It was up to the discretion of call operators to give CPR advice, he said.