Computer Sciences Corporation (CSC) has announced plans to cut 640 members of staff over the next three months in a move hailed as necessary to align with the changing IT services market.
However, UK union Unite has argued the reduction in CSC staff is a result of cuts to its failed NHS contract.
The US IT services giant was responsible for delivering a fully integrated patient and medical records system throughout the NHS, but in October last year, the CSC had to repay £174m because of the project's failure.
CSC declined to confirm why or where the business cuts were being made but confirmed the losses would take place.
"We can confirm that we have started a formal 90-day consultation process in the UK which could reduce the number of people working in our UK business by an anticipated number of 640 people," said the company in a statement.
"This action is necessary because the IT services market is changing, and our customers want competitive, new services with different contract and delivery models."
The CSC said it hoped to reduce its staff numbers chiefly through voluntary redundancies and redeploying people, but may also need to make compulsory redundancies.
Unite has argued the compulsory redundancies are not needed. It added that CSC has now announced 1,100 job losses in the UK since February.
"This announcement of a further 640 job cuts has dealt our members a severe body blow and left them absolutely devastated," said Unite national officer Kevin O'Gallagher.
"We have put forward a detailed plan which will avoid any compulsory redundancies in the company, however, these plans have not been taken up and CSC is insistent on issuing compulsory redundancy notices despite receiving sufficient number of volunteer requests to leave the company."
Last week, Unite members from CSC's Chesterfield, Chorley, Leeds and Solihull sites took part in lunch-time protests over the company's refusal to listen to proposals which could mitigate any compulsory redundancies.
CSC entered into a 10-year contract with the NHS in 2002 to deliver the National Programme for IT (NPfIT), with the intention of providing an individual electronic care record for every UK resident that could be rapidly transmitted between different parts of the NHS system.
However, the NPfIT soon ran behind schedule and over budget. The system was meant to be delivered by 2004 at a cost of £2.3bn, but this rose to somewhere between £12bn and £30bn.
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