Barclays is cutting 1,700 frontline jobs from across its branch network.
The bank has told staff it will be cutting frontline branch roles next year, including cashiers, personal bankers, operational specialists and branch managers.
Barclays says the cuts reflect the increasing numbers of customers looking to do their banking online and through smartphones.
The bank says as a result it wants to “invest in the channels that customers are using, while improving customer service”.
A spokesman says: “As a result of technological changes, we will be able to provide better service for our customers with fewer staff in our branches.
“Today we have outlined a voluntary redundancy scheme for those colleagues who are interested.
“We are committed to working with our impacted colleagues so that they are fully consulted and have access to the support and services they require.”
Unite national officer Dominic Hook says: “It is a colossal mistake for Barclays to announce 1,700 job cuts across its bank branches. Such a massive reduction will be very detrimental to the bank and will also be hugely challenging for the staff remaining.
“Unite is pressing Barclays to reconsider this proposal. By taking 1,700 of the workforce away Barclays risks massive reputational damage.”