An administrative bungle led to Tasmania's ambulance fleet being driven around unregistered for the second time in six years.
The fleet was unregistered for 16 hours on Thursday before Ambulance Tasmania became aware of the error and insured the vehicles.
Health Department secretary Kathrine Morgan-Wicks said there were no reported incidents while the vehicles were unregistered.
The failure follows a 2017 incident where the fleet of more than 100 vehicles was unregistered for six days.
During that time, they attracted 14 speeding fines and prompted assurances that changes would be made so the bungle would not be repeated.
Opposition health spokeswoman Anita Dow said it was "extraordinary" that the error had occurred again.
"This is another example of a government that just can't get the basics right and it's simply unacceptable that the government would put our paramedics at risk and Tasmanians at risk being driven around in unregistered vehicles," she said.
"Tasmanians just want to get access to care in a timely manner and the government's putting them at risk by not getting the simple things right."
Ms Dow questioned why details of the bungle were only revealed in a press release distributed at 4pm on Friday, a day after the Health Department became aware of the error.
The 2017 failure was only revealed following a Right to Information request from the Opposition.
"This government's got form when it comes to releasing information late in the day and I'm not surprised by that," Ms Dow said.
