Dublin Bus want the drivers on some of the new cross-city routes servicing the expanding suburbs of north Dublin to begin, end and break their shifts in the city centre as practiced in other depots located within the city.

But Siptu and the National Bus and Rail Union argue that when around 500 drivers agreed to transfer out of the city centre garages to Harristown, near Dublin Airport, in 2004, they were led to believe that all shifts would start and finish there.

"Since the opening, drivers have developed a lifestyle that has revolved around the depot, as its location near the M50 and M1 allows them to easily calculate the time they needed to arrive and start at the garage, " argued the unions at the Labour Court last week.

The same drivers who now don't want to leave Harristown secured a 3,700 disturbance payment for the "inconvenience" of transferring there in 2005.

The dispute is a major embarrassment to the company as, initially, the then transport minister Seamus Brennan was reluctant to hand over the new buses as it was contrary to the government's policy of encouraging competition in the transport sector.

The fact that 25 of these buses remain idle will also militate against the state transport company which wants more new buses to serve the city's expanding suburbs.

Dublin Bus told the Labour Court that drivers were never assured that they would not have to start or end shifts in the city centre like most other drivers.

"Failure in introducing the new schedules is damaging the reputation of the company and causing great hardship to potential customers in new developing areas of the city, " it added.

The new routes affected are the No. 4, which links Ballymun to Blackrock, and the No. 128, which goes from Baldoyle to Rathmines.

The chairman of the Labour Court, Kevin Duffy, backed the company's stand and said the drivers should accept city centre breaks on these routes.

A spokeswoman for Dublin Bus said that the company accepted Duffy's ruling and hoped the unions would do likewise.

The spokeswoman also confirmed that Dublin Bus is currently in talks with the Department of Transport over a fares increase early in the new year. Last year Seamus Brennan approved a 7% hike in fares.

Also last week, the company announced the sale of 47 doubledecker buses which are currently in use but will be pulled out of service between December 2007 and January 2008.