Train drivers have voted overwhelmingly in favour of industrial action at Irish Rail.

The dispute centres on payment for past productivity.

Members of the National Bus and Rail Workers Union (NBRU) voted by a margin of 95% to engage in industrial action.

NBRU General-Secretary Dermot O'Leary said it relates to "the company's refusal to honour the Labour Relations Commission agreement of the 3rd of September 2014 which provided for discussions on the contributions which train drivers have delivered over the last number of years".

While 92% of SIPTU drivers voted for the action.

SIPTU says the company has reneged on a commitment to discuss past productivity, and if they do not honour the terms of that agreement it will inevitably lead to disruption of services.

The union will meet on Thursday to decide what form the action will take.

SIPTU organiser Paul Cullen said: "The result of this ballot, which saw 92% of drivers vote in favour of industrial action, indicates the level of frustration felt at the company's refusal to honour an agreement it entered into in September 2014".

"Our members still hope that management will step back from the brink and honour the terms of this agreement to negotiate on past productivity produced by drivers", he added.

Irish Rail have said they will only discuss extra pay in return for more productivity.

"Our message to trade unions would be that disrupting our customers is totally container productive. We are available to discuss productivity, if we agree verifiable cost savings through productivity," said Barry Kenny, Corporate Communications Manager for Irish Rail.

"We will share that benefit between the company a d employees so let's not cause unnecessary hardship for customers, and the company and employees as well and let;s get that dialogue underway," he added.