Monaghan County Councillor Colm Carthy has said south Monaghan is working with two less primary care nurses than usual.
He said he spoke with a local nurse recently who told him there is currently three nurses doing the work of five in the area.
While one nurse has been promoted to a management role within the HSE, another is on long-term sick leave.
Mr Carthy said this was a "situation which cannot be allowed to continue" and called on the HSE to begin recruitment to make up the shortfall.
He said in south Monaghan, where the population is ever-increasing, vulnerable people including the elderly and new mums are being advised and triaged over the phone.