Level three COVID restrictions will be imposed on Co Donegal as early as tonight.
The Cabinet is meeting over the phone this afternoon to consider advice from the National Public Health Emergency Team.
The latest figures for Donegal show the county has moved above 122 cases per 100,000.
When Dublin was moved to level three last week, the capital had a lower 14 day incident rate of 114.2.
The figures for Derry and Strabane in Northern Ireland, neighbouring Donegal, have now hit 141.4 cases per 100,000.
The cabinet is meeting in-corporeally this evening to discuss the rapid escalation.
It had been expected a decision wouldn't be taken until next week, but the rise in cases in Donegal has led to a quicker intervention.
Government sources have suggested that will be the only county moved to level three.
A full announcement is expected later this evening.