HSE ambulances broke down and required roadside assistance more than 200 times last year, new figures have revealed.
A 24-hour breakdown and recovery service had to be dispatched on a total of 203 occasions during 2016 in response to callouts from stranded emergency ambulances.
The only previously available data regarding ambulance breakdowns relates to a nine-month period in 2015, during which 235 NAS vehicles required roadside assistance throughout the country.
Almost 5 per cent of the National Ambulance Service (NAS) fleet currently has more than 300,000kms on the clock, while one ambulance is still in service after travelling over 400,000kms.
Since 2010, vehicles used by An Garda Síochána have been retired at 300,000kms for safety reasons.
It is not known whether any such guidelines are in place for the NAS.
Concerns about the condition of the national ambulance fleet have been raised in the past in response to incidents in which major mechanical faults were discovered while emergency vehicles were in service.
In August 2015, the two back wheels fell off an ambulance that was transporting a patient on life support from Letterkenny, Co Donegal to University Hospital Galway (UHG) when it was travelling through Co Mayo.
A year earlier, an ambulance broke down in Co Louth while it was transporting a heart-attack patient to hospital. A second ambulance had to be dispatched and a journey that should have taken less than 25 minutes took over an hour.
Around the same time, it was reported that another ambulance in Co Louth was abandoned by its crew when the front of the vehicle filled with smoke. There was no patient on board at the time.
Of the 203 breakdowns that occurred last year, 45 occurred in the Dublin area and 63 occurred elsewhere in Leinster. A total of 25 ambulance breakdowns were recorded in Connacht, 46 took place in Munster, and 24 occurred in Donegal, Cavan and Monaghan.
The county in which the highest number of breakdowns was recorded outside of Dublin was Kildare, where ambulances required roadside assistance on 16 occasions during 2016.
There were no breakdowns in counties Roscommon, Offaly and Longford; while just one breakdown was reported in each of counties Leitrim and Kerry.
In 2015, the then minister for health Leo Varadkar announced a €9.4 million fleet replacement programme for the NAS, under which 64 vehicles were to be commissioned to replace older ambulances.
Under this 53 emergency vehicles were decommissioned in 2015 and replaced 64 new ambulances.
The HSE capital programme for 2016 provided for the purchase of an additional 50 new ambulances and the refurbishment of 35.
The data, which was released by the NAS under the Freedom of Information Act, shows there are currently 265 vehicles in the ambulance fleet operated by the HSE.
The HSE has declined to comment.