The Labour Court is set to hear from the Irish Congress of Trade Unions, Luas drivers and operator Transdev next week.
The body is considering whether or not it should intervene in the long running dispute over pay.
It follows the twelfth day of strike action yesterday, which brought the capital to a halt and discommoded 100,000 commuters.
In a meeting last night SIPTU agreed to support shop stewards if the row escalates.
Several more stoppages are planned this month and next, the union's Owen Reidy has said a Labour Court intervention would be positive.
“The Labour Court will obviously have to make up their own mind next week - having heard Congress, having heard the employer representatives - if they feel there is scope for an intervention,” said Reidy.
“If they do (intervene) that would be a positive and a useful thing, if they don’t obviously the dispute continues. ”