Elsewhere, Professor Jeremy Brown, a member of the Joint Committee on Vaccination and Immunisation (JCVI), warned a “very large number” of at-risk people could develop a “serious” Covid-19 infection if restrictions are lifted now.
"The scars are deep. Independence would be Brexit Mark 2."
Andrew Lynas told MPs that buying mozzarella cheese from one of his long-standing suppliers in England now requires eight separate processes under the Northern Ireland Protocol.
"These adverts claim that British business is going from strength to strength.... and ignores the alarm bells they have been sounding", the letter reads.
A letter notifying the British government of impending infringement proceedings will be issued on Monday.
A £160 charge on a case of Italian wine has got Brexiteers scratching around for British Barolo.
Hauliers worried about paperwork errors holding them up are reluctant to use the port in North Wales.
The UK suffered a 14.7 per cent fall in goods exports - one of the largest slumps of any major country - in 2020.
"I hope they will shake off any remaining ill will towards us for leaving, and instead build a friendly relationship, between sovereign equals," he said.