Ambulance officers are risking the sack from St John for wearing mufti shirts while tending to the sick and injured, a union says.
However, St John is upholding its militant employees' "rights" to wear a badge that states: "Healthy Ambos Save Lives."
First Union has encouraged its members at St John to take industrial action, technically a strike, by refusing to comply with the uniform policy.
The union wants a 2 per cent pay rise for members and says St John has offered 1.25 per cent. The union also wants members to get the benefits of all 11 public holidays, saying that on average they are restricted to seven because of St John's rostering practices. The union says St John has offered an increase to eight.
Full time ambulance officers earn a national average of $67,576.05 a year.
Union members claim they are seriously overworked and often don't get full or any meal breaks.
One, who has not been named, said that after working four shifts of 13 to 14 hours, "you are barely able to function by the end".
"That's when you sleep for 10 to 12 hours every day off and still feel the night-shift hangover for three days afterwards. That's when you miss out on seeing your kids or partner for days on end."
The strike, which ends at midnight tonight, is considered unlawful by St John because three other unions pulled out. First Union disagrees.
Union representative Lynette Blacklaws said members had been threatened with dismissal for wearing the union's campaigning badge.
But St John's clinical operations director, Norma Lane, said not so.
"We respect employees' rights to express their feelings in a professional manner such as wearing a badge.
"However, if employees make the decision to wear mufti and cannot be identified as St John ambulance officers, there is a genuine health and safety risk to patients, especially children and other vulnerable patients.
"There is also a significant potential risk to our ambulance officers when they cannot be identified as a St John ambulance officer by the public or other emergency workers."
Lane said St John may take disciplinary action "to protect patient and staff safety" as a last resort.
"Throughout the industrial action our ambulance officers have conducted themselves professionally; there has been no disciplinary action and no issues have been brought to our attention by our staff or by our managers," she said.
Lane said St John was still hopeful of reaching an agreement.
Blacklaws said members were still showing their St John identification cards. She had not heard of any members being subjected to disciplinary action for wearing mufti and St John had withdrawn legal proceedings attempting to stop the strike.
She said some members had been "intimidated" into thinking they might be disciplined. A station manager told members that "if someone dies because they didn't let you in, be it on your heads".
"This kind of emotional blackmail is unacceptable," Blacklaws said.