Staff at HBOS and Lloyds TSB face an uncertain future after it emerged the banks were in advanced talks about a potential £30bn merger.
HBOS is the largest mortgage lender in the UK, but has been hit by recent weakness in the property market and its shares after the collapse of Lehman Brothers investment bank.
Trade union Unite, which represents staff in both banks, said employees would be “very worried” about the consequences of a merger.
Deputy general secretary Graham Goddard said: “Unite is calling for urgent talks at the highest level with the banks. We will not accept any compulsory redundancies as a result of this merger.
“The country is in the grip of a credit crunch and the cost of living is spiralling. Lloyds TSB and HBOS must take a socially responsible approach to this merger and make the wellbeing of their hard-working staff a priority during these difficult times.”
Unite said it would work with other staff unions, such as the Lloyds TSB Group Union which has 45,000 members, to ensure there was a co-ordinated effort to support staff.
At the start of the year, Lloyds TSB announced it was axeing a third of its HR team as part of a shake-up of business operations.