The Irish Road Haulage Association (IRHA) has called on the Minister for Transport to abandon his "ludicrous" plans to ban large lorries from entering Dublin city centre after the opening of the Port Tunnel.
Otherwise the maximum permitted height for the tunnel must be raised, the group said.
It said the proposed ban - combined with the Dublin Port tunnel height restriction of 4.65 metres, would reduce competitiveness, increase pollution, increase traffic congestion, and increase costs for the consumer.
"Super-cube" vehicles are on average 30cm taller than existing trailers and due to methods of packaging can accommodate 50 per cent more than their smaller counterparts.
More than 360 heavy goods vehicles a day will be affected by the restriction, which was announced by Mr Brennan earlier this month.
He said all lorries importing goods to the Republic through Dublin Port "will be required to use the Port Tunnel when the tunnel opens in 2005". The restriction effectively excludes larger trucks from using the port.
"This is ludicrous," IRHA spokesman Mr Jimmy Quinn said.
"The use of 'super-cubes' in Ireland will cut down on traffic and help reduce pollution. It will also reduce distribution costs for products that are sent throughout Ireland. For the Minister to ban them from Dublin Port makes no sense.
"England is our biggest land trading partner and you can drive a 'super-cube' from Galway to John O'Groats and the only obstruction will be the Dublin Port Tunnel and the Dublin City centre. This issue needs to be addressed and I am calling on the Minister to revoke his proposed ban for everybody's sake," he added.
