HP has announced internally that 934 jobs will be axed in the UK by October.
According to Unite union, HP has a 16,500-strong workforce in the UK, which could also be affected by a further 1,000 job cuts from November, which the union said is a "proportional" part of the 9,000 job cuts worldwide that the company announced last month.
The union is planning to meet with HP in the next two weeks for negotiations.
In a statement, HP said: "[The proposed changes] were first discussed with the HP European Works Council in November 2009 and have been part of an ongoing consultation process since then."
HP also said that the "proposed changes" were "part of the company's ongoing review of its business".
However, Unite said that the latest round of job cuts was particularly painful after seeing nearly 4,000 jobs being cut over the past two years since HP took over EDS.
"This will create further insecurity and uncertainty in HP with the threat of yet more redundancies to come," said Peter Skyte, Unite national officer for IT and communications.
"Our aim is to reduce and to avoid compulsory redundancies. The fact that the company still retains nearly 2,000 temporary staff and contractors merely adds insult to injury," he added.
Although Skyte said that it is "too early" to say whether the union members would go on strike in response to the job cuts, he did not rule out industrial action.
In April, after a series of strikes and talks through the Advisory, Conciliation and Arbitration Service (ACAS) regarding a dispute over pay and redundancies, Public Commercial Services (PCS) union were in the process of finalising the details of a pay and redundancy offer for staff working on the Department for Work and Pensions contract. PCS was unable to provide a status update at the time of writing.
Meanwhile, Skyte warned that the job cuts at HP meant that that fewer people were having to do more work.
"Managers are concerned that they don't have enough people to do the work," he said, saying that work for clients, including Rolls Royce and the Ministry of Defence, could be affected.
Unite also said that workers at HP sites in Bracknell, Bristol, Hook, Erskine, Milton Keynes, London and Warrington are likely to be affected by the jobs cull.
Last month, HP was forced to pay BSkyB a total of £318 million in full and final settlement of a high profile lawsuit over a failed CRM implementation by EDS ten years ago.