Financial services union Amicus says it has become "increasingly concerned" about the prospect of job losses at Abbey's operations in Scotland after the bank cancelled a meeting with the union at the last minute.
Amicus says it had arranged to meet with senior officials at Abbey, which has just been taken over by Spanish banking group Santander Central Hispano, but the meeting was cancelled at "the eleventh hour".
The union says it wanted to seek assurances over jobs at the bank's Scottish Provident and Scottish Mutual businesses after a remark made by Santander chairman Emilio Botin raised fears among Abbey staff in Scotland.
Amicus claims that, when quizzed about the future of the Scottish Mutual and Scottish Provident businesses, Botin responded by saying he was "not committed to anything".
The union believes a meeting last Tuesday betwen Abbey executives and MPs about the future of the two businesses might have been be a charm offensive to pave the way for bad news at a later data.
Abbey went on to cancel a later meeting arranged with unions.
Hugh Scullion, Amicus regional officer, says: "Abbey should prioritise staff security rather than cancel meetings with us.
"We want firm assurances from the company over job security to boost morale, rather than schmoozing MPs in order to pave the way for bad news."
In January this year Abbey said it was moving 400 call centre jobs from Warrington and Derby to India as part of a major overhaul of its UK operations. The bank also announced plans to close its Scottish Provident offices in Edinburgh and transfer the 900 jobs there to its site in Glasgow.
Furthermore, in July Santander disclosed details of a three year, £300 million cost cutting plan at the UK bank which included a reduction in middle and back-office processing.