Dublin Bus have urged drivers not to get involved in the dispute at the Harristown garage ahead of a protest march tomorrow.
The National Bus and Rail Union (NBRU), which represents 3,700 employees of the three CIE groups, plans to march from Parnell Square to Dublin Bus headquarters on O'Connell Street at 11am tomorrow.
Yesterday, the union's general secretary, Michael Faherty, warned that unofficial pickets could be placed on other garages. He said this would be regrettable but remained a possibility.
If there is a large participation in tomorrow's march, the union may feel it has the backing of its members to place unofficial pickets on other depots.
Dublin Bus today appealed to all drivers to work normally tomorrow. Siptu, who also represent Dublin Bus drivers, believe the Harristown dispute is a local one and should not involve drivers from other depots.
Siptu said tonight it had accepted an invitation from the Labour Court to attend talks there tomorrow.
"We have accepted the invitation and would urge all the other parties to do so as well," Sitpu branch organiser Willie Noone said. "This dispute needs to be resolved quickly in the interests of the general public as well as our members in Harristown."
The dispute over two new routes at Harristown garage has meant that for a second day, 27 bus services from the depot were cancelled, and there is disruption during peak times on 11 other services, affecting almost 60,000 passengers.
More than 100 drivers at the north Dublin garage began industrial action yesterday after a female driver, who refused to drive a bus on one of the new routes, was suspended by Dublin Bus management.
The drivers are also opposed to new scheduling that means they will have to start, break and finish work in the city centre.
There has been no indication as yet of any third-party intervention in dispute. Drivers at Harristown have already rejected proposals put forward by the Labour Relations Commission and the Labour Court.
A Dublin Bus spokeswoman said last night that it was concerned about a possible escalation of the dispute to six other garages in the capital.
The spokeswoman said that the company would "seriously consider all its options" if unofficial pickets were placed on other depots. She said Dublin Bus was open to talks but only on the basis of the drivers going back to work and operating the new routes.
The main areas affected are Finglas, Swords, Ballymun, Blanchardstown, Donabate, Portrane, Dunboyne, Littlepace, Tyrrelstown, Damastown, Portmarnock, Kinsealy and Kilmore.
The following routes have no service: 4, 13, 13a, 17a, 27b, 27c, 33b, 37x, 39x, 39b, 40, 40a, 40b, 40c, 40d, 40n, 70x, 83, 102, 105, 127, 129, 142, 230, 237, 238, 239.
The following routes have a limited service: 27x, 37, 38/a, 38c, 39, 41, 41c, 41x, 43, 70/a, 270.
Dublin City Council said tonight the bus lanes on the N2 from the M50 to Hart's Corner are to be temporarily suspended for the duration of the bus dispute to help ease traffic congestion in the Finglas area.