Luas drivers are threatening they could stike 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.
Transdev, which runs the Luas, says it will pay for cooler bags for the packed lunches of tram drivers since they lost access to a fridge.
They used to store their meal at the Sandyford depot where they would return to eat it.
But since the new line opened, they now must carry it to Broombridge and eat it there.
SIPTU isn't happy with the cooler bag solution and wants five extra drivers to be hired at a cost of 250-thousand euro a year, which would allow them to continue returning to Sandyford.
The Labour Court says it doesn't usually concern itself with the function of cooler bags but has asked they be risk assessed.
SIPTU says a ballot of drivers is likely to reject that proposal, meaning industrial action could be on the cards.