Last month, Barclays announced it would close the scheme to 18,000 exisiting members and according to trade union Unite, 92% of staff have voted for a ballot on strike action over the firm's proposals.
Derek Simpson, Unite joint general secretary, said: "It is unacceptable that Barclays is proposing this unilateral change to workers' pensions. Unite members will not stand by as their employer rides roughshod over their retirement security.
"The workforce views this pension proposal as a betrayal by their employer. Consultation with our members has shown the depth of anger over the pension issue.
"The forthcoming ballot within Barclays will send a strong message to private sector employers across the economy. Unite will not accept businesses using the economic downturn as a means to erode the important terms and conditions of members.
"We would urge Barclays to go back to the drawing board in order to avert damaging strike action."
Unite currently represents 25,000 Barclays staff. The ballot is to take place in August, with a potential strike planned for September.
A Barclays spokesman told HR magazine: "Barclays regrets Unite has signalled its intention to ballot for strike action.
"It is our firm belief that the interests of all stakeholders are best served through continued open dialogue. We are therefore disappointed that Unite have chosen not to re-engage having previously walked away from discussions.
"Barclays stands by the security of pension benefits already built up by employees and is committed to ensuring that pension provision is sustainable, equitable and affordable.
"We will continue to consult and communicate with our employees. In the event that any disruption led by Unite should occur, we will take all necessary steps to deliver continued service to our customers and clients."
