The EU has been accused of acting "mischievously" after it impounded a lorry because the driver didn't have customs papers for his lunch.
The farcical situation emerged when jobsworth officials in Dublin wouldn’t let the M&S lorry enter Northern Ireland despite all the paperwork being correct.
Determined to find fault, they then questioned whether the driver had documentation for a sandwich sitting in the cab which he had bought for his lunch.
When he failed to produce it, the lorry was forbidden from crossing the border, according to Archie Norman, the chairman of Marks and Spencer.
Speaking to the Telegraph he accused the EU’s customs union rules of dating from a “bygone era when the system was deliberately protectionist and the technology primitive”.
When the UK formally left the bloc in January this led to huge problems - especially with highly perishable products which rely on a modern and fast-moving system to arrive at the shelves on time.
Speaking to columnist Charles Moore, Mr Norman said the EU was being “plain silly, or mischievous, or both”.
The M&S chief also insisted that these problems could be sorted out “100 percent” if the EU showed willingness.
Mr Moore added: “Short cuts are not allowed. It is not possible to get, say, monthly clearance for butter from a particular depot which can then cover all sandwiches thus buttered.
“The butter for each sandwich must be individually cleared. For agri-food imports, eight documents are required per lorry, amounting to 720 pages.
“Some M&S documents have been refused solely because they have been written in blue ink rather than in black.
“There are comparable problems for garden plants and trees, medicines and pets.”
The information emerged after Mr Norman warned that M&S is already cutting Christmas products in Northern Ireland due to concerns over forthcoming post-Brexit customs checks.
Mr Norman told the BBC that the current "pointless" checks with the Republic of Ireland were "threatening" to its business.
He called for a "common sense approach to enforcement."