Unite regional secretary for Ireland Susan Fitzgerald said: “This is a huge win. Seagate is one of Northern Ireland’s leading manufacturers and if a union can be built there – in the face of such a professional and well-financed anti-union campaign, then it can be built anywhere.

“This result will be noticed by workers right across the economy, most especially in the northwest. Now is the time for workers to join a union and secure a collective voice.”

Unite said that following the result, the employer has 30 days to negotiate a voluntary collective bargaining agreement with the union or else have a statutory one imposed by the industrial court.