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
Storm Imogen - when and where we will see the strongest winds? ITV Weather's Manali Lukha gives the breakdown.
Kate Middleton attended a special service to celebrate the landmark occasion in her first engagement as Honorary Air Commandant
The ISIS execution gang fronted by 'Jihadi John' had two British extremists who learned radical Islam together in London, ITV News reveals.