Business lobby group Ibec is worried that UK plans to charge lorries for using roads will cost businesses in the Republic some €60 million each year.
Ibec yesterday pointed to an independent economic consultancy study which finds that the new lorry road charges will cost the haulage industry in the North more than €30 million annually.
The lorry road user charge could be expected to cost hauliers in the Republic double this amount, according to Ibec.
The body has called on the Government to urgently raise the matter with the UK authorities.
The new charges are set to be introduced in Britain and the North during 2007 and 2008 and will apply to all roads. The move is designed to be cost-neutral for hauliers in Britain, who will benefit from a fuel duty rebate.
In the North, however, this rebate is expected to be ineffective because most Northern hauliers buy their fuel in the Republic where it costs less.
The impact of the charges will be particularly acute for hauliers from the Republic because of their need to use the "UK land-bridge" to access European markets, according to Ibec.
He believes that the charge will act as a barrier to free trade and must be questioned under European law.
The consultancy report on the North also predicts that some industry will divert its business to ports in the Republic to avoid paying charges in ports such as Larne or Belfast.