Workers at Dublin Bus are to ballot for strike action.
The vote, which will take place next Thursday and Friday, is a ballot for industrial action - up to and including an all out strike.
The National Bus & Rail Union (NBRU) says the ballot is due to the failure of Dublin Bus to honour the terms of the Workplace Relations Commission document agreed upon by workers.
In particular they are concerned about the failure to restore the normal link between pay and pensions.
Dermot O'Leary of the NBRU says workers are angry.
"Look we're experiencing difficulties as people know," he said. "You have a breech in agreement by a State-owned company."