The Unite union, which represents many Barclays workers, says the bank's decision to cut up to 1,700 jobs is 'a colossal mistake'.
The union said frontline roles, including cashiers, personal bankers, operational specialists, branch managers and assistant managers will go throughout 2014.
It claimed that customer service would be affected by the changes and said Barclays risked damaging its reputation.
In a statement Barclays said fewer of its customers were using branches.
More top news
Up to 10cm of snow could hit parts of Britain today as forecasters predict a cold snap in the lead-up to the New Year.
Hacking group Lizard Squad claimed responsibility for the attack which left thousands struggling to access their accounts for hours.
Three men broke into a house on Christmas morning but when the owner said he had no money they took his pets instead.