Emergency financial aid could be needed to shore up food exporters finding the “door to the EU is now shut”, an industry head has said.

James Withers, chief executive of Scotland Food and Drink, said the trade system is “failing” and predicted problems will worsen this week.

He warned orders will be cancelled and EU customers will look elsewhere for their goods as he called for urgent action to fix the post-Brexit trade issues.

The crux of all this is sheer complexity & lack of prep time

In a series of tweets, he said: “More messages from food exporters who are finding the door to the EU is now shut. Haulage firms won’t take their loads; bureaucratic/IT systems failing.

“A multi-billion pound trade system is being tested for the 1st time, in real time. And it’s going wrong.

“Brexit, week 1 was bad. Week 2 will be worse. UK Govt’s dismissal of the request from us (& most main business orgs) for a grace period was a critical mistake.

“By this time next week, pressure to revisit that will be even greater. Emergency financial aid may also be necessary.

“The crux of all this is sheer complexity & lack of prep time. For a product that has 24hrs to get to market, small delays at diff points are crippling.”

He said the “simplified” process for moving fish from Scotland to France involves 18 steps.

Mr Withers added: “For those that say businesses had years to prepare, a reminder that the final Border Operating Model (all 160+ pages) was published 6 hours before the end of the transition period. Yes, 6 hours.

“We wrote to UKGov with 100 days to go warning that UK could not be ready & asking for a grace period. With 60 days to go, we wrote to @BorisJohnson making the same plea. There was no willingness to even ask the EU about it. Mistakes of 2020 are done. 2021 fixes now critical.

“The pain of Brexit this week will be much less visual than many expect. It is unlikely to be the queues of lorries on motorways or on airport runways in Kent. It will be the pain of what is NOT happening: cancelled orders and EU customers starting to go elsewhere for their goods.”

His comments follow some fishing and seafood companies describing the new arrangements as a “shambles” as red tape led to delays.

Cabinet Office Minister Michael Gove warned on Friday he expects more disruption at the UK border in the coming weeks.

Mr Gove told broadcasters: “So far disruption at the border hasn’t been too profound but it is the case that in the weeks ahead we expect that there will be significant additional disruption, particularly on the Dover-Calais route.

“It is our responsibility in Government to make sure that business is as ready as possible, and hauliers and traders have already done a lot but we have to redouble our efforts to communicate the precise paperwork that is required in order to make sure that trade can flow freely.

“So over the course of the next few days, Government will be stepping up that communications effort to make sure that business knows what is required.”