Luas drivers have warned they could strike over the issue of packed lunches.

A row has erupted since the opening of the new tram line changed the location of drivers' break-time.

They used to store their meals at the Sandyford depot, where they would also return to eat it.

However, since the extended Green Line opened last December, drivers now must carry their lunch to Broombridge and store it in fridges there.

Transdev, the company which operates the Luas, says it will pay for cooler bags for the packed lunches.

However, the SIPTU union is not happy with the cooler bag solution and wants five extra drivers to be hired at a cost of €250,000 a year.

That would allow drivers to continue returning to Sandyford.

The Labour Court has said it does not usually concern itself with the function of cooler bags, but has asked they be risk assessed.

SIPTU has said a ballot of drivers is likely to reject that proposal, meaning industrial action could be on the cards.