Greenkeepers at the K-Club are readying themselves for a showdown over pay and working conditions seven months before the course hosts the Ryder Cup.
"There was a change in ownership and management last year, and since then conditions have deteriorated," said Colm Quinlan, regional officer for the Amicus trade union.
Nobody at the K-Club, which was bought privately by businessmen Michael Smurfit and Gerry Gannon in 2005, could be reached for comment.
Mr Quinlan, who met around 30 K-Club staff last month to discuss grievances over wages, rosters and possible outsourcing, said greenkeepers had not received a cost-of-living pay rise last year despite already being on "a very low base of pay".
Staff responsible for preparing the course for the 36th Ryder Cup, contested by Europe and the America, and to be played in Ireland for the first time in September, earn less than €10 an hour, which is "behind the normal rates for comparable employment", said Mr Quinlan.
The State's legal minimum wage is €7.65 an hour. Amicus, which had just six members at the club prior to last month's meeting, received "a steady flow" of membership applications since then, according to Mr Quinlan, who added that his request to discuss the issue with management had been rejected.
The Co Kildare club had said in a written reply to the union that it acknowledged the right of staff to become members but had a constitutional right of its own not to recognise a union on collective issues.
"I will be taking stock of the situation at the end of the week and then writing to the company again," said Mr Quinlan. "If I don't get a satisfactory response we'll be referring the issue to the Labour Relations Commission."