HP services engineers are set to strike for 10 days, and to refuse overtime, in a fiercely fought battle over pay and benefits.

The news comes as HP faces a separate strike from 1,000 ex-EDS public sector IT workers. Both strikes will impact work next week.

The services engineers will first strike on Monday (7 December), then on 11 and 12 January, followed by 1 and 2 February, and 22 to 26 February. They will refuse to work overtime from 4 January.

Their complaint is around being transferred on 1 November into the HP CDS business, which was formed from the acquisition of Synstar in 2004. Alongside the move the staff are losing pay and pension benefits, including a £2,000 performance bonus scheme and a final salary pension, trade union Unite said.

HP told its customers that it did not expect the strike to have "any effect" on service. "In cooperation with our clients and the involvement of our company-wide global delivery capabilities, we will take the necessary measures to deliver the services that our clients require," a spokesperson said.

The supplier said it "respects" the decision by the staff to strike, adding that it will attempt to avoid the strike by engaging in further dialogue.

But Unite sees the matter differently. It said HP has treated them with “contempt” over the issue. The company was taking advantage of weaknesses in current employment legislation, it said, in order to remove the pay and pension benefits.

Unite accused the company of failing to engage with it over the issue. “This dispute would be relatively easy to resolve, if HP would agree to sit down with us and talk with us,” said Andy McDowall, regional officer. “We urge them to return to the negotiating table."