Computer giant Hewlett Packard, which has a site in Birmingham, is to axe 1,300 jobs in the UK and switch work overseas, union leaders have said.
Unite branded the news "butchery", saying the cuts came on top of 900 job losses announced in June to take place by the end of October.
Nearly 4,000 jobs have now been cut by the company throughout the UK over the past two years, with the figure now set to rise to almost 6,000, said Unite.
National officer Peter Skyte said: "Despite significant profits HP appears hell-bent on continuing to butcher its highly skilled UK workforce. It is increasingly difficult for HP employees in the UK to plan for their futures when the threat of redundancy is continually hanging over their heads. Morale is at an all time low.
"Lax employment protection in the UK compared to other European countries means that the UK is bearing the brunt of cuts, as it's quicker and cheaper to sack UK people and export their jobs abroad."
Unite said the cuts brought into question the Government's assumption that the hi-tech private sector will spark growth and new jobs in the UK.
"These job cuts mainly involve the export of jobs to HP locations outside the UK," said Mr Skyte.
"On the evidence of these cuts, the UK Government's belief that the hi-tech private sector will be the motor for growth and new jobs is largely a mirage."
In addition to Birmingham, the company has sites in Belfast, Bracknell, Bristol, Derby, Erskine (Scotland), Hook (Hampshire), London, Milton Keynes, Newcastle, Peterlee, Sheffield, Uxbridge, Warrington and Washington.
The company said: "HP is in consultation with the appropriate representative bodies within the UK regarding potential workforce changes which were announced on June 1, 2010.
"This is an initiative to transform HP's enterprise services business to benefit clients through new offerings and improved service delivery."