UP TO 70,000 commuters trying to get to work and college today were caught in travel chaos as the Bus Eireann drivers' strike deepened.
The dispute has entered its second day with no resolution in sight.
Drivers are refusing to operate their vehicles over moves by Bus Eireann to introduce cost-cutting measures to save €5m annually.
While yesterday's industrial action mainly affected tourists and families, today's disruption had massive knock-on effects for the wider business and trade sector of the country, as staff battled to get to their workplaces.
Siptu drivers joined their NBRU (National Bus and Rail Union) colleagues in strike action yesterday. Bus Eireann said there are 600 coaches off the road.
It has 1,800 drivers, with 1,000 of them in the NBRU and the remaining 800 in Siptu.
It operates on 300 routes, with some services, such as the Dublin-Belfast one, operating around the clock.
Bus Eireann's Andrew McLindon said that around 70,000 people use its services daily and will be affected by continuing strike action.
"Our commuter network for Dublin alone stretches as far as Cavan and Wicklow, with others coming from as far as Wexford, and the same level of disruption can be expected while the NBRU and other drivers continue their industrial action," he said.
"We apologise to all our customers for this disruption, but we must stress that we have been in talks with the union for the last 11 months over cost savings needed to save Bus Eireann.
"This strike is not only affecting workers trying to get to their jobs, but also students in third level who are facing exams around now."
Meanwhile, a fresh row has broken out between Transport Minister Leo Varadkar and the NBRU after the union claimed he had issued specific instructions to Bus Eireann about the dispute. NBRU General Secretary Michael Faherty claimed that the Minister had told the bus company not to engage in negotiations.
However, in a statement this morning, Mr Varadkar rejected the claim. saying: "I totally reject Michael Faherty's assertion on RTE Radio 1 this morning that I have issued any instructions to Bus Eireann management.
"As I have stated repeatedly, I fully support management in its efforts to put the company's finances on a sustainable footing and protect jobs. The NBRU also has a role to play in that process, but can only do so by re-entering negotiations.
"Tens of thousands of passengers are being inconvenienced today by this industrial action. I urge the NBRU to take swift action and re-enter negotiations without preconditions immediately."
Mr Faherty said that it is impossible to predict how long the strike will last.
"The only person I think that could answer that question is the Minister for Transport. I'm saying that because he has taken over control of this dispute so he is the only person that could answer the question."
Bus Eireann said it expects its school bus service will not be affected and should run normally this week, but asked parents and guardians to check www.buseireann.ie and national and local media for further information.
The strike action is not expected to spread to the Dublin Bus or Irish Rail networks, with representatives from both saying they are run as different companies and their drivers are not involved in the same dispute.
"We have been running a full schedule and will continue to do so," Dublin Bus and Irish Rail told the Herald.
Tanaiste Eamon Gilmore said the strike is not good for the travelling public who are inconvenienced by it.
"All strikes, all disputes, are ultimately resolved in discussion and negotiation and the sooner that that happens, the better," he said.