The Government says it is not satisfied with the loss of the afternoon flight between Donegal and Dublin.
The Taoiseach said all flights on the route would have ceased if a new contract had not been signed with Emerald Airlines yesterday.
Micheál Martin was responding to criticism from Donegal Deputy Pearse Doherty, who said the agreed Public Service Obligation contract does not include the afternoon service, widely described as a lifeline for those travelling for medical appointments.
Campaigners from Donegal Cancer Flights and Services travelled to Dublin to present a petition with more than 15,000 signatures calling for the schedule to remain unchanged.
The Taoiseach said entering the contract was necessary to protect the route, adding that the Government is not satisfied with the reduction in service and will keep the matter under review:
