Transport chiefs have "gone into hiding" rather than trying to resolve a row with bus drivers ahead of a fresh two-day strike, union leaders have claimed.
As the capital's commuters brace themselves for another 48-hour stoppage by Dublin Bus, trade union Siptu said no-one will sit down with them to negotiate an end to the action.
Organiser Owen Reidy said talks were the only way forward.
"As always, Siptu representatives are available at any time to enter into serious negotiations aimed at finding an agreed resolution," he said.
"Unfortunately, as of now, there is no-one sitting at the other side of the table."
However, Dublin Bus has insisted it is open to negotiations, under the terms of a Labour Court recommendation.
Servces will halt at 9pm on Wednesday evening.
The strike was due to begin at midnight, but Dublin Bus has ordered their fleet to be back in depots three hours earlier for what it says are health and safety reasons.
It is expected to affect 400,000 passengers each day and will also hit Friday's hugely popular annual Culture Night across the city.
In a statement, the company again apologised to customers for the inconvenience and disruption.
"Dublin Bus accepted the Labour Court recommendation of a pay increase of 8.25% over three years for all employees across the company," a spokeswoman said.
"This is above the norm of approximately 2% per year across the public and private sector.
"We believe this pay increase to be fair and reasonable."
The company said a request for a 15% pay increase from trade unions would cost it €50m over the next three years and would seriously hit its financial stability.
It added every day of strike action was costing Dublin Bus €600,000.
"We remain willing and open to engage with the trade unions and urge them to return to talks as provided for in the Labour Court recommendation, so that we can work together to move forward and find a resolution to the current dispute," the spokeswoman said.
The city was hit with two days of traffic gridlock last week as people turned to private cars and taxis - which reported a threefold jump in business - during a two-day strike.
The walkout by members of the National Bus and Rail Union (NBRU) and Siptu was the first of three planned for this month.
A further stoppage is planned for September 23 and 24.