Cadbury Ireland is to seek up to 450 redundancies at its Coolock manufacturing plant in Dublin.
The job losses, announced by the confectionery company yesterday, are blamed on higher wages and increasing costs in areas such as energy and insurance, will be staggered over the next two to three years and will reduce by almost a third Cadbury's total workforce in Ireland.
In a statement, the company said it had briefed staff of a "change programme" centred on redundancies, adoption of new technology and modernisation of work practices.
If successfully carried out, these changes would "restore competitiveness" to the Coolock factory, while investment of more than €100 million would follow over the next three years.
"Our priority at the moment is to continue to communicate with all of our employees, and this follows our tradition of sharing future plans with employees at the earliest opportunity," the company said.
Cadbury stressed that it was committed to manufacturing in Ireland and had already invested €80 million here since 1999.
Staff were told of the redundancies at several briefing sessions throughout yesterday, the last of which was due to take place at 10pm.
A Siptu spokeswoman said the union was aware the company was seeking "substantial changes" but would await an assessment from shop stewards before commenting directly. She noted, however, that Cadbury had committed itself to maintaining production in Coolock.
A company source suggested that rising wages and costs such as energy and insurance were to blame for the redundancies. "Cadbury wants to remain here, but it's a very competitive environment and the objective is to maintain competitiveness."
Energy bills had increased by 30 per cent between 2003 and 2006, the source said, and this was putting a strain on Cadbury and other employers across the manufacturing sector.
According to a recent Forfás report commissioned by Minister for Enterprise, Trade and Employment Micheál Martin, the number of jobs in the sector fell by 31,000 in the five years to the end of 2005, following a 30-year spell of expansion in manufacturing employment.
Responding to news of the job losses, Fine Gael Dublin North Central TD Richard Bruton blamed the Government for ignoring the State's rising cost base.
"This is a massive blow to the Cadbury staff, many of whom have given years of service to the company," he said.
Industrial electricity prices are 30 per cent higher in the Republic than in the UK, Mr Bruton said, while gas is 20 per cent more expensive here.
"The huge pressures on our manufacturing base are being ignored by the Government. Cost pressures are coming from direct cost increases imposed by Government and from its failure to prevent the heavy knock-on costs of expensive housing and the construction boom," he said.
Labour Dublin North East TD Tommy Broughan said the job cuts would be a "hammer blow" for Coolock, parts of which had an unemployment rate of 25 per cent.
"Cadbury Ireland has a long connection with the Coolock area, and had a great tradition of providing secure and relatively well-paid employment for local people," he said.
Cadbury currently employs some 1,500 people in the State.
As well as 1,100 staff in Coolock, 100 employees are based in Rathmore, Co Kerry; 50 work in Tallaght; and the remaining 250 operate between sites.