Fine Gael TD Joe McHugh has called on politicians in Northern Ireland to back a campaign to save Malin Head Coast Guard station, the world's oldest maritime radio rescue centre.
He said its closure would be detrimental to the safety of people in the North as well as the Republic.
Mr McHugh, TD for Donegal North East, said: "Malin Head has been in operation since 1902 and plays an integral part in the security and safety of all in the northwest and beyond. It is essential that it does not close.
"I would call on all politicians from all parties, North and South, to oppose the decision to downgrade the centre. Malin provides a local knowledge-based service and this must continue."
The Coast Guard service plans to reduce operations at Malin and at Valentia Island, Co Kerry. Critics believe downgrading will eventually lead to total closure.
Minister for Transport Noel Dempsey backs the plan to replace the bulk of their functions with new centres in Drogheda and a site yet to be chosen on the west coast.
Thirty-four jobs are at stake at Malin Head and Valentia.