Employers' group Ibec has criticised the Dublin Port Tunnel authorities over a recent spate of unplanned closures which it says are causing commuters and hauliers major inconvenience.
Paul Sweetman, from Ibec's transport executive, said: "Unplanned closures of the tunnel are occurring on an almost monthly basis. This frequency of closures cannot continue."
Yesterday, systems failures forced the tunnel to be closed for nine hours causing severe traffic congestion across the north city.
Mr Sweetman said: "When the tunnel is repeatedly closed due to systems failures, strong and decisive action is required.
"The tunnel is now an integral part of the transport network and is a crucial link for the movement of people and goods across the capital," he added.
The National Roads Authority (NRA) and Dublin City Council yesterday initiated legal proceedings against the builders of the tunnel over repeated systems failures.
The NRA and the city council are said to have consulted legal advisers after it emerged the latest problem involved a malfunction of the tunnel's electronic systems.