The Labour Court is set to hear from the Irish Congress of Trade Unions (ICTU), 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 12th day of strike action yesterday, which brought the capital to a halt and discommoded 100,000 commuters.
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In a meeting last night, SIPTU agreed to support shop stewards if the row escalates.
Several more stoppages are planned this month and next.
SIPTU's Owen Reidy says a Labour Court intervention would be positive.