Guinness manufacturer Diageo has announced it is to close its brewing facilities in Dundalk and Kilkenny with the loss of up to 250 jobs.
The company intends to rejuvenate its St James's Gate Brewery in Dublin city and invest €650m in the historic site.
Diageo estimates that the sale of property and lands in Dundalk and Kilkenny will raise €500m.
Workers at Diageo's plants in Dublin, Waterford, Kilkenny and Dundalk were being briefed by management this morning.
Diageo says 93 people are directly employed in its brewing operation in Kilkenny.
It is understood that there are possibly another 50 people employed in the Kilkenny brewery on short term or temporary contracts.
Brewing has been taking place in Kilkenny for almost 300 years.
Mayor of Kilkenny City Marie Fitzpatrick said the news has come as a major shock.
Ms Fitzpatrick said the area where the brewery is located is a vibrant part of the city.
She said staff at the plant had suspected some element of downsizing, but not a full closure.
Diageo employs 85 people at its Dundalk brewery.
800 people are employed in Diageo's brewing operation, which also manufacturers Smithwicks, Kilkenny and Harp.
Staff at Diageo were told this morning that employees affected by the change will be offered relocation packages where possible, but severance packages, career counselling and outplacement support will also be made available.
It is announced plans to develop a new brewing facility close to Dublin, but the exact location of the new facility has yet to be announced.
Speaking before the announcement on RTÉ Radio's Morning Ireland, General Secretary of the Guinness workers' union Sean Mackell said that any proposals made by the company this morning will be subject to negotiations over the coming months.
He said that the unions would be utterly opposed to compulsory redundancies and would consider them totally unreasonable.
Too bad for those guys but at least they are not closing and selling the historic St. James Gate Brewery