Around 140 Bank of Ireland staff are picketing the bank's offices on Baggot St and Dawson St in Dublin this morning as part of a row over pension entitlements.
The striking staff are all Amicus union members. Union officials say 100 staff are outside the bank's head quarters on Baggot St with a further 40 outside the bank's New Ireland Assurance office on Dawson Street.
The union claims to have up to 500 members in the bank.
The dispute centres on the bank's introduction of different pensions for new staff joining the bank, which unions claim confer lesser entitlements than existing pensions.
The pickets are not outside bank branches and it is unlikely the customers will be inconvenienced. If there is no resolution of the dispute, Amicus plans to picket the bank's offices in the IFSC, Dublin, on Wednesday week.
If the situation has still not been resolved by then, the union will meet to review its strategy before considering possible escalation.
Talks at the Labour Relations Commission (LRC) failed to resolve the dispute, although Colm Quinlan, regional officer with the union said this morning that "communication lines with the LRC remain open".
The main union representing bank officials, the IBOA, has deferred a ballot on industrial action.