Fujitsu workers across the UK have given notice of five days of strike action between 22 January and 8 February.
The move follows on from a five-day strike by members of the Unite union which took place two weeks ago, as part of an ongoing dispute over pay, the closure of a final salary pension scheme and 70 planned redundancies by the end of January.
There was also a one-day walkout in December, marking the first ever national strike at an IT company.
More specifically, Unite has called upon 1,454 members to take industrial action on January 22 and 29, and February 1, 5 and 8.
In addition, its members in Northern Ireland will strike on January 26 while members in Scotland, England and Wales will also strike on January 27, when a parliamentary lobby by senior Unite representatives from key Fujitsu sites is set to take place.
Meanwhile, the House of Commons has tabled an Early Day Motion by Tony Lloyd MP in support of the workers, calling for Fujitsu and Unite to negotiate a settlement to resolve the dispute.
Unite said it had been threatened with an injunction to ban the strike action, which then backfired when Futjitsu admitted that it had overlooked the notice the union had sent on January 15.
Peter Skyte, Unite national officer for IT and communications, said: “Fujitsu should be focusing on serious negotiations with Unite rather than spending money on expensive lawyers in a fruitless and ultimately counterproductive attempt to use the law.”
“We still believe that this dispute can only be resolved by Fujitsu sitting down with us to address the issues of the jobs, pay and pensions.”
In a statement, Fujitsu said: "Fujitsu is disappointed that the Unite trades union has decided to continue to take industrial action whilst consultation continues with the elected employee representatives on the proposed changes to the pension scheme.
"Fujitsu has taken prudent measures to ensure that service to its customers is maintained.”
Action will target a number of major Fujitsu contracts, including Marks & Spencer, Vodafone, the Home Office, HM Revenue & Customs, Defra, the Financial Services Authority, and the Post Office.
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