Spokesperson for the ambulance staff, SIPTU's Dermot O'Loughlin says they are focusing on the expenses involved in running the service.

"They are carrying out a report into the feasibility and viability of the service, " said the head of the union's Civil Aviation branch.

"We are not sure why they are doing it. It is causing some concern with the ambulance workers. We know they have to look at these issues from time to time but it's a very important service, " he added.

The airport's ambulance service receives a hundred calls a month and has saved eight lives in past five years. "The response times are excellent and the number of calls we receive would put this service on a par with a small town with 21.2m passengers going through the airport every year, " said O'Loughlin The DAA say they are just carrying out a routine review but would not offer any further comment "We are carrying out a full-review of all the different aspects of the ambulance service and that is all we will be saying on the matter, " said a DAA spokeswoman.

The DAA are currently in an industrial dispute with the airport police and fire service over an occupational injury scheme but have reported positive dialogue with the labour relations commission and are due to meet again next week.

The DAA say they are confident that a resolution can be agreed. "The chairman of the talks has put forward proposals and we went away positively from them. We would be very hopeful of a positive outcome from it, " said the DAA.