The Irish Business and Employers' Confederation (Ibec) today threatened Dublin City Council with a law suit over its plans to bar heavy goods vehicles (HGVs) from the capital's streets.
Councillors have voted in favour of banning five-axle trucks from the city centre during the daytime two months after the port tunnel opens later this year.
But Ibec warned the move could be illegal and claimed it will compound gridlock on roads around the capital.
Reg McCabe, Ibec transport director, said: "Preliminary legal advice suggests that the City Council is exceeding its authority by curtailing HGV access to Dublin Port and is in breach of EU free movement provisions.
"This short-sighted and ill-conceived plan will add to the traffic chaos on the M50 and will only make life more miserable for the thousands already stuck in Dublin gridlock."
Dublin City councillors have voted to ban trucks with five axles or more from the city centre - between the Royal Canal and the Grand Canal - between 7am and 7pm. Trucks will also be barred from accessing the port via East Wall Road on the northside and Sean Moore Road on the southside from January 1st, 2007.
The council recommended that vehicles with five or more axles be hit with the ban within two months of the tunnel opening, but that trucks with four axles should be allowed to use the city for port access until the M50 upgrade was completed.
But last year the European Court of Justice struck down a similar HGV ban by the regional government of Tyrol, Austria, on the ground that is was disproportionate and interfered with the free movement of goods.
Jimmy Quinn, Irish Road Hauliers' Association chief executive, said the council should apply a stay of execution on the HGV strategy and at the same time ban trucks from the quays.
"It would stop people using the quays and still have the key shopping areas open for vehicles to deliver. We are talking about common sense, and these other people are talking dogma and ideology."
Ibec said the Government should intervene and force the council to lift the ban pending a full economic impact assessment.