Some 260 jobs are under threat this evening after two companies announced plans to close their plants in Carlow and Cork.
Car component maker Lapple Ireland is to close its manufacturing plant in Carlow with the loss of 140 jobs.
Elsewhere, electronic components maker Molex announced its intention to close its plant in Millstreet in Co Cork - which employs 120 workers.
Lapple Ireland, set up in Carlow in 1974, is a subsidiary of Lapple, and manufactures press tools and sheet metal components for the car industry. At its height, the plant employed over 350 employees.
In a statement today, management said the closure was due to the plant incurring heavy losses in recent years. It said the business had been "seriously impacted by the increasing competitive and cost pressures that are affecting Ireland's manufacturing sector".
The company said it would immediately enter into negotiations with staff representatives on redundancy terms and that the plant will cease operations later this year.
Taoiseach Bertie Ahern said the job losses were bad news for Lapple and its employees but denied the economy was losing its competitive edge.
"Overall the employment is holding up well," he said. "We can never take our focus off improving competitiveness and trying to win direct foreign investment. There are more of the new Eastern countries trying to win investment, and we just have to get sharper. If we stay still we will lose ground."
Minister for Enterprise, Trade and Employment Micheál Martin said the Carlow closure of "underlines the ongoing challenge facing the Government and the country as a whole".
Fine Gael enterprise spokesman Phil Hogan said today's news was further evidence that Ireland's competitiveness is being eroded by rising costs and greater competition from overseas.
"Fianna Fáil fought the election on the basis of the economy, but the truth is that the party has done nothing about competitiveness for the last five years," he said.
Labour TD for Kildare South Jack Wall said Lapple's announcement is the latest in a list of job losses and represents a serious setback to the town and to the Carlow and South Kildare regions.
It also emerged that 120 Cork jobs were under threat today after Molex announced plans to consolidate its Irish operations at its Shannon plant.
The company employs 600 workers at its plants in Shannon and Cork. Management is understood to be meeting workers in both plants.
The company was first established in Shannon in 1971, and the smaller plant in Millstreet was opened in 1984. It is a subsidiary of the giant Molex Corporation, which has its headquarters in the United States.