Talks aimed at averting a national rail strike are also underway
Unions at Dublin Bus have told management to make a new offer, if they want to reverse the threat of strike action by the end of the month.
SIPTU says three grades have already voted to take industrial action, and they are now waiting to see what their remaining members decide.
Divisional organiser Owen Reidy says they will be in talks today - and probably Wednesday.
He says while they are willing to negotiate with management, they cannot do that on their own.
Meanwhile talks aimed at averting a national rail strike get underway today.
SIPTU and the National Bus and Rail Union (NBRU) are attending discussions with Irish Rail at the Workplace Relations Commission (WRC).
Yesterday, the unions suspended the holding of a strike ballot in order to attend the talks.
Train drivers are looking for a shorter working week and recognition for past productivity.
NBRU General-Secretary Dermot O'Leary is optimistic about the chances of success.