IT is a story The National began to look into because a number of our readers pointed out that Tesco had started to rebrand Scottish strawberries as British.

Now it has resulted in a major farmer telling us that his proudly branded Scottish strawberries may soon not exist and that the Scottish soft-fruit industry could “collapse overnight” due to Brexit.

As we have continued our Save Our Scotland Brand campaign, our enquiries have found more and more evidence that Scottish produce will disappear from our shelves, not because of Union Jackery – the replacement of the Saltire mark with the Union Flag – but because the Scottish items themselves could become extinct.

One of the biggest success stories in Scottish farming has been the growth of the soft-fruit sector which has seen soaring sales of Scottish strawberries, raspberries, blackberries and blue-berries.

It is a real Scottish achievement, and the importance of maintaining the branding of Scottish soft fruits is paramount. But The National can today reveal the threat to the entire industry in Scotland.

For how can you brand Scottish strawberries and other soft fruit with the Saltire when farmers may not be growing them any more?

The berry-growing industry in Scotland and the UK in general is almost entirely dependent on migrant workers, mainly but not exclusively from Eastern Europe.

Almost 20 months after the Brexit vote, the UK Government has still not put in place any arrangements for migrant workers to come to Britain for the seasonal picking jobs.

Soft fruits must be hand-picked and sorted, and migrant workers are the best at the job – indeed in many areas they are the only ones who can do the job.

One major Scottish soft fruit farmer told The National that unless migrant workers are allowed in to pick his strawberries, he will have to stop growing them.

John Mitchell, of Allanhill Farm, near St Andrews in Fife, said: “We do not know what the final decision is going to be on migrant workers but if we can’t get them we’ll have to stop growing the crop.

“There’s no mechanical picking method available so if we cannot get the migrant workers that would be it – we would just have to pack up.

“It’s the same across the whole sector, and there’s already been uncertainty with farmers not making investments because everything is up in the air.”

Mitchell has been in the strawberry- growing business for 22 years and says his business is totally reliant on migrant workers, mainly from Poland, Bulgaria and Romania.

He said: “The last British person to work here at picking the fruit was eight years ago. There are just not enough British people interested in doing that sort of work.

“In the UK we have had the lowest unemployment figures for 40 years, and there’s just not the people available to do the job, even if they wanted to do it.

“In every fruit-growing area there are hundreds of migrant workers coming each summer for the picking and then they go home so they do not add to the immigration statistics – they are true migrant workers.”

Mitchell says the obvious solution is to revive the former Home Office seasonal agricultural workers scheme which was scrapped by Theresa May when she was Home Secretary.

Mitchell said: “That worked well and a lot of growers used that scheme across the UK, and then when some of the countries they were from became full members of the EU we didn’t have to use that scheme.

“Surely, even as a temporary measure, that scheme could be started again, otherwise I fear our sector will collapse overnight.”

Mitchell is adamant that the fact that his fruit is branded as Scottish is a good selling point.

He said: “The market is still growing and it has been a success story when other agricultural sectors have not been doing so well.

“Because of our climate, our fruit is some of the best in the world and, in England in particular, Scottish soft fruit is seen as a quality product that people want to buy, which is why farmers here make sure the Scottish origin is on the label.”

That branding remains hugely important, but unless the UK Government acts on the issue of migrant workers, it won’t matter as there will be nothing to brand.