"The company has yet to produce any proper justification for this latest attempt to raise profits by cutting pension benefits, and this action may hinder future bids for blue chip private sector outsourcing contracts."

"We will be mounting a robust campaign to persuade the company to think again."

But a Fujitsu spokesperson said: "The decision was made with regret. The reason was to reduce costs to remain competitive. Our customers are looking to cut costs and if we don't have that competitive edge, we may not get that business."

has made a number of cutbacks to its employee benefits in recent times, curtailing bonus payments in 2008 and putting in place a pay freeze during 2009.

Unite also accused Fujitsu of not allowing staff to attend medical appointments in work time and cutting 'out of hours' payments, but Fujitsu spokesperson denied this was a policy and said the company has a grievance programme for complaints.