Workers at the Fujitsu plant in Birmingham are to be balloted on strike action after the electronics firm announced plans to axe 140 jobs.
Last week, the telecoms equipment division said it wanted to move manufacturing to the US to increase efficiency.
However, the Communication Workers Union (CWU) said staff were angry at the decision and would fight to save the jobs.
Bill McClory, CWU deputy general secretary, said: “This is a factory that only six weeks ago was praised by Gordon Brown and that is performing as well as the Fujitsu plants in Japan and the US. Under these circumstances, the company must reconsider its decision.”
The company said it expected to redeploy 30 staff to other areas of the company and had begun a 90-day consultation with staff over the proposals.
More than 700 people are employed in total at the Solihull site.