I HAD a Scottish grandmother and she drilled into me the phrase that you are better to keep quiet and let people think you are stupid, rather than open your mouth to prove beyond all doubt they were right.

Boris Johnson clearly lacked the benefits of a Scottish grandmother or anyone else to temper his speak-first-think-later approach. This week he claimed the undoubted success of the UK vaccine roll-out was down to the twin outcomes of greed and capitalism. This was not only a silly off-the-cuff supposed joke, but factually wrong.

Success is in fact down to researchers and others that strived to create a vaccine in record time, and to the army of medics and volunteers getting jabs into patients' arms. It is equally not down to capitalism, since UK developed vaccines are effectively being sold at cost. Johnson rolled back on these comments, but as my grandmother would have said, once you have shown your stupidity there is no going back.

Wisdom is knowing when it is best to say nothing – a lesson Johnson has never learned. With those few words he handed the moral high-ground in the vaccine row back to the EU at a crucial point in discussions between London and Brussels. This is doubly unfortunate, because vaccines are the fig leaf protecting the government from the fallout around trade problems linked to Brexit.

There has to be growing concern that trade issues are a one way street. Recent weeks have seen the Irish and others that supply food to the UK welcoming the fact that they will not face any checks or restrictions before October at the earliest. This is because the UK has not got the systems in place to implement its own rules, despite talking tough right up to its Christmas Eve climbdown about being ready for a no deal Brexit.

The Irish Farmers Association, its main farm lobby organisation, said the UK 'no restrictions' approach would bring months of stability to its dairy and beef sectors. This is because business as usual will continue and brings extra time to prepare for the changes that lie ahead.

This should come as no surprise. The UK government, unlike the EU, is not greatly interested in protecting the integrity of the UK food supply chain against possible threats. It is more interested in keeping consumers happy with well stocked supermarket shelves, knowing that shortages blamed on Brexit would dent its assurances that the policy is working.

At the same time the government has said it wants to move its focus in diplomacy and trade away from Europe – which the rest of the world sees as a prime, high value food market – towards the Indo-Pacific region. That is a choice the government is free to make, but it is one that does not appear to hold out a lot of opportunities for agriculture.

At the same time as the government was admitting it will not be able to restrict or control imports from the EU, figures emerged from HMRC showing that in January food exports collapsed. The big losers were whisky, chocolate and cheese – with cheese sales alone down from £45 million to £7 million on a year on year comparison.

Separately, the Office for National Statistics said that from December, when the UK was still in the single market, to January, all UK exports to the EU were down by 40%. For food, this was confirmed in the European Commission's trade statistics. These show that even before January, UK food exports to the EU were falling faster than any loss of EU to UK trade. Ironically the worst hit trade route was from the UK to Ireland, once the UK's biggest. This happened amidst signs that Irish suppliers, despite initial fears, are feeling no or very limited Brexit impacts.

The bottom line, according to HMRC, is that food and drink exports fell in January by 75%. There are reasons for this – stockpiling by customers before Brexit became final, Covid taking away key export sectors linked to catering amongst them – but this remains a far from encouraging picture.

Defra claims trade recovered in February towards more normal levels, but those statistics are yet to emerge. Unless they offer significant signs of improvement, it will be hard to escape the conclusion that the problems besetting the Scottish fishing industry are just the tip of a very large post-Brexit trade iceberg.