Greenkeepers and hotel staff at the K Club in Straffan, Co Kildare, have been told they are to be put on a maximum three-day week in January and part of February.
The employees were given the news this week and told by management that the move was due to cost-saving measures. They were also told the hotel would be closed for about 2½ weeks after the new year.
Amicus trade union will be contacting K Club management immediately with a view to starting negotiations about the cutback in the working week.
Colm Quinlan, Amicus branch secretary, said the employees had only just heard about this.
"They have been told that cutting back to a maximum three- day week is necessary due to cost-saving measures. That's all they've been told," he said.
He would contact the K Club on Monday with a view to starting talks about the cutbacks.
It is believed the cutbacks would begin after the new year and continue at least into part of February. Nobody from the K Club responded to a press query yesterday.
News of the cuts comes just days after it was announced that the K Club has received the green light from Kildare County Council for an extension that will more than double its hotel in size.
A 9,000sq m (96,875sq ft) extension will contain 90 bedrooms, 47 of which will be suites varying from one to three bedrooms.
The number of rooms will be 159 when the extension is completed.
The extension will allow the K Club to capitalise on the considerable success of the Ryder Cup last September, which received worldwide publicity.
Meanwhile, Mr Quinlan said the union would be going back to the Labour Court to clarify issues concerning greenkeepers' pay.
Last August, the greenkeepers voted to accept Labour Court recommendations which allowed for a 50 per cent pay rise within the next 18 months.
The proposal was to introduce six phased pay increases dating back to April 1st this year and continuing to January 2008. The workers' pay would be increased from €9.87 an hour to €14.50 within 18 months.
The dispute between management and greenkeepers centred on the pay rates at the K Club, with the union claiming staff were paid less than €10 an hour when the standard rate was €15.
At one stage, the greenkeepers had threatened to strike during the Ryder Cup.