“Our argument is that there should be a frictionless border,” said Carolyn Fairbairn, director-general of the Confederation of British Industry (CBI).
“We are sceptical about the technical solutions, and we will continue to make the economic case,” she told reporters in Brussels.
Her comments echo those of Foreign Minister Simon Coveney, who told the Irish Independent last month that an “e-border” using technology would be a non-runner.
The Government is keen to keep talks between the EU and UK at the political level regarding Ireland.
The CBI says solutions, such as electronic pre-clearance and automatic numberplate recognition cameras – which are used at the Swedish-Norwegian border – will not be in place by the time the UK leaves the European Union in 2019.
“These kinds of projects take a long time to deliver,” said Ms Fairbairn. “The idea that we’re going to have something like that ready in March 2019 – a lot of our members are very sceptical about that.”
The CBI is pushing for the UK to remain in the single market and customs union for a transition period post-Brexit, at least until a wide-ranging free trade deal, which could take years, can be struck.
It hopes to agree that transition period by October or November to give companies time to do their investment planning.
According to a CBI survey published last week, 40pc of UK businesses say Brexit has affected their investment decisions, with 98pc of those saying the impact has been negative.
However, companies are not trying to “turn back the clock” on Brexit, Ms Fairbairn said, but are trying to “make it work” for them.
She said companies have “not given a lot of thought” to asking the British government for a contingency fund or a relaxation of state aid rules, suggestions the Irish business and employers’ federation (Ibec) made in a June position paper.