And 40pc said that using a longer, yet more direct, route would adversely affect the quality of the product.
But 30pc of exporters quizzed for the survey by the Irish Exporters Association (IEA) have taken no action to assess the fallout from the Brexit vote, even though 70pc said a weakening sterling had impacted their business.
Marie Armstrong, IEA vice-president, said the number of exporters relying on the UK as a land bridge to the continent was "hugely significant".
"And those members are very concerned about continuing to use the UK in terms of customs, and being stopped at borders," Ms Armstrong told TDs yesterday.
For more on the survey's findings click here.