Unifi, which claims to represent more than 60% of the 9,000 staff in Barclays' IT division Enable, has told members that is concerned that the terms and conditions of Barclays' staff may gradually erode if their jobs are transferred to IBM.
Any dispute between Unifi and IBM, which does not recognise trade unions, could lead to delays in Barclays' plans to outsource large sections of its IT work, including IT infrastructure management, its automatic teller machine network and branch office systems.
In a circular to union members, Unifi said it was being consulted over the possible large-scale transfer of parts of Enable to third-party suppliers. "We welcome consultation but have to say that we do not welcome the transfer of jobs out of Barclays," it said.
The union is concerned that laws designed to protect the terms and conditions of staff transferred to new employers under outsourcing agreements will not provide Barclays' IT staff with any long-term guarantees.
"Without recognition we are concerned that any agreement we hammer out will not be kept on the other side [of outsourcing]," said Keith Brookes, Unifi's national secretary. "We are in discussions at the moment. We want full recognition, not cosmetic recognition."
The union, which has a partnership agreement with the bank, has told its members that it will examine Barclays' business plans closely and challenge the bank if there is no clear business case for outsourcing.
The union has previously reached agreements with other Barclays outsourcing companies including Xanasa, and IPSL, a joint venture between Lloyds TSB, Barclays and Unisys.
"This was an excellent agreement. We got union recognition and although there were some redundancies, they were three or four years down the line, and the terms were thrashed out before the transfer," said Brookes.
According to the union circular, Barclays' discussions with IBM and other outsourcing companies are still at an "early stage". Options under consideration range from outsourcing parts of the bank's IT systems to total outsourcing or a joint venture.