TSB Banking Group (LSE:TSB) is closing 36 branches and axing 250 jobs as it continues its focus on digital banking.
Job cuts will take place in the group's fraud department and for workers at the closing branches, a spokesperson for Unite union revealed, before labelling the choice a "grave mistake".
TSB said: "The decision to close a branch is never taken lightly, but our customers are now doing most of their banking digitally and we need to move to a better balance of digital and face-to-face services.
"We remain committed to a national branch network and through innovation and integration with video, telephone, digital, branch and other face-to-face services TSB customers have more ways to bank with us than ever before."
Andy Case, a Unite regional officer, responded to the decision: "At a time when customers are increasingly concerned about financial fraud and often need support from a local bank branch this is the wrong course of action."