Bus Éireann workers are backing Labour Court recommendations aimed at ending a long-running dispute at the company.
It is after the row over pay and conditions brought the service to a halt for 21 days earlier this year.
The company has warned on several occasions its facing imminent insolvency if it cannot find a way to cut costs.
SIPTU and UNITE trade unions have voted in favour of Labour Court ruling.
However, the results of the NBRU ballot will not be released until next week.