The Irish Bank Officials' Association is believed to be considering all options, including industrial action, to force the bank to delay the closure of the pension scheme to new recruits.

Under sweeping reforms announced earlier this year, employees recruited from 1 October will no longer be covered by the existing scheme, which guarantees a pension linked to pay and length of service. Instead, they will be offered an alternative "hybrid" arrangement with watereddown guarantees.

The move is being challenged by the IBOA, which wants the controversial changes to be shelved until all industrial relations machinery has been exhausted. A meeting of the executive group representing the union's 8,000 members at Bank of Ireland has been called for later this week.

The pension row threatened to scupper a new national pay deal earlier this year, as unions pressed for greater protection for new recruits to ensure they benefit from the same pension entitlements as existing workers.

IBOA general secretary Larry Broderick has described the bank's decision as "morally reprehensible" and "an example of the worst type of corporate greed".