HP staff represented by the Public and Commercial Services union have announced a series of 48-hour strikes over the next three weeks.
Up to 1,000 members will be carrying out industrial action on 29 and 30 March, and 6 and 7 April.
The length of industrial action has been extended from the two days that Jim Hanson, national officer at PCS, had suggested was possible.
The strikes will take place in the north east and north west of England, and will affect HP Enterprise Services' IT contracts for the Department for Work and Pensions, the Ministry of Defence and General Motors.
The union said that members have continued work to rule, in addition to the three days of strike action carried out by staff in Newcastle, Washington, Preston, Lytham St. Annes and Norcross earlier this month and in January.
In addition to the strike action, the union plans to launch a petition and seek the support of MPs.
Mark Serwotka, PCS general secretary, said: "The escalation of their campaign illustrates the determination of HP staff to achieve guarantees on job security and a fair pay rise. The company needs to start valuing its own workforce and negotiate a settlement that addresses the concerns of the workforce."
The industrial dispute centres on pay freezes, as well as on the 3,400 EDS staff who have been made redundant since HP took over the company in 2008, and the 1,000 job losses planned for the first half of the year.
The strikes last week took place as non-IT workers in the civil service, also in the PCS union, staged simultaneous high-profile action affecting a range of central government and judicial services.
The dispute between PCS and HP has been going on since December 2009, when HP narrowly avoided a strike by union members by agreeing to sit down to talks at the eleventh hour.
After a one-day strike in January, Hanson said the union had had a couple of meetings with the mediation organisation Advisory, Conciliation and Arbitration Service (ACAS), but that HP "wasn't willing to move far enough."
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