Aerospace giant Rolls-Royce has come under fire for announcing hundreds of job losses.
Unite said 320 posts were being axed, mainly at the firm's Derby and Bristol sites, describing the cuts as "unnecessary".
Rolls-Royce said the number of people it employed in the UK will remain constant or grow in the coming year.
A statement said: "However, in order to increase production and to stay competitive the mix of our workforce needs to change, with more people in frontline engineering and production jobs and fewer in support functions.
"Wherever possible we will redeploy people and we will seek to avoid compulsory redundancies. Last year, we recruited more than 300 people on to our graduate schemes and will recruit more. We also took on another 300 apprentices and that number will grow in the year ahead."
Unite's national officer Ian Waddell said: "Rolls-Royce is a massive success story in UK manufacturing, making record profits and with a booming order book. The company needs the support of its employees to continue this success story and fulfil its commitments to its customers.
"Another round of redundancies in these circumstances, on top of the 400 job losses proposed in its defence business, is a criminal waste of talent that will create insecurity and damage morale in the workforce."
He added: "We want Rolls-Royce to prosper as this will provide job security for current employees and future job opportunities for our young people.
"I urge Rolls-Royce to abandon this plan and talk to the union about measures to further improve competitiveness without cutting loyal staff. The company does not need to disrupt the workforce in this way when it is demonstrating global success and creating huge profits."