Kenny's appearance at the conference, being held in Newcastle, Co Down, could increase the pressure on the bank to delay the closure of the pension scheme to staff recruited from tomorrow.

The IBOA, which bitterly opposes the move, wants the bank to wait pending negotiations at the Labour Court and the government's partnership watchdog, the National Implementation Body.

Larry Broderick, the IBOA general secretary, accused the bank of "breathtaking arrogance" and announced that the union plans to ballot its 8,000 members at Bank of Ireland for industrial action.

A spokeswoman said the bank was disappointed by the union's threat of strike action, claiming the proposed changes to the pension scheme were in the best interest of current and future employees.