The HSE, paramedics and Siptu representatives will face questions today from the Oireachtas Health Committee concerning ambulance response times.
It is part of a review ordered by the Health Minister James Reilly after it emerged that crucial response targets were being missed.
The HSE, paramedics and Siptu representatives will answer questions regarding the response targets.
Siptu has welcomed the review - to be carried out by the HSE and the Health Information and Quality Authority - and has also asked that they take into consideration the level of resources available to the ambulance service.
Chair of the Health Committee Jerry Buttimer said the public had to have confidence in the service.
He said the aim of today's meeting was "so that we can get an understanding of what's happening on the ground from the perspective of the first responders and from those charged with managing the responses".