SIPTU has announced that it will ballot Dublin Fire Brigade members for strike action over a failure to secure four additional ambulances.
SIPTU said the additional four ambulances are needed to meet service demands in the city.
"The Health Information and Quality Authority (HIQA) has identified that there is a capacity issue in relation to the operation of the ambulance service in Dublin," said SIPTU's Brendan O'Brien.
"The management of Dublin Fire Brigade (DFB) has advised Dublin City Council that it is prepared to put four additional ambulances on the streets immediately so that its Emergency Medical Service (EMS) can achieve HIQA targets.
"However, senior management in Dublin City Council has stated that it is not in a position to provide the ambulances."
SIPTU said this will leave the DFB unable to provide a necessary ambulance service for Dublin dwellers.
"In December, senior management of Dublin City Council was informed by SIPTU members that if the DFB was denied the resources necessary for it to achieve its HIQA targets it would automatically trigger a ballot for industrial and strike action," said Mr O'Brien.
Mr O'Brien said SIPTU is calling on the Government to provide the financial resources to allow for the provision of the four ambulances.
"This situation is completely unacceptable to our members as it places the public, communities and businesses at unnecessary risk as well as placing undue and unsustainable strain on DFB paramedics," added Mr O'Brien.
Meanwhile, IMPACT National Secretary Peter Nolan said: "Our members in the DFB will be consulted over the coming days with a view to also proceeding with a ballot for strike action due to this unacceptable situation."