The HSE spent 14.3 million euro on taxi services in the first six months of this year.
Taxis are often used when an ambulance isn't needed, such as transferring a dialysis patient from their home to hospital.
The HSE also spent 4.5 million euro on private ambulance services in the same time frame.
David Hall's Lifeline Ambulance Service, based in Leixlip, got over 1.4 million euro.
He says private providers should be used to deal with serious cases - not just non-urgent calls.
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