Would you work on a remote British farm, putting in long days picking fruit and digging up potatoes in the countryside? It is easy to see such work in a romantic light, like something out of the Darling Buds of May. But it is mostly the opposite. Long hours, low pay, dirty conditions and physically demanding work.

This is why British producers of fruit and vegetables are so worried. Most of us would answer no to the above question without a second thought. In a recent report, the chairman of a large produce firm, said that “no British person wants a seasonal job working in the fields. They want permanent jobs or jobs that are not quite as taxing physically.”

So companies like this rely on up to 70,000 foreign workers to pick, sort and pack fruit and vegetables. They are more willing to get their hands dirty for low pay. The same is the case in many other British industries. Not many of us want to be employed cleaning up a slaughter house, for example, so eastern European workers are vital.

But this arrangement is now seriously at risk following the Brexit vote. The British Growers Association has warned that if these seasonal workers are not given special permits to enter the country, the whole industry will be in dire straits. Labour shortages would probably force producers to close or relocate overseas.

This might seem like just another economic problem. But it holds implications for national security according to Erica Consterdine from the University of Sussex’s Centre for Migration Research. For her, the failure to consider the importance of these foreign seasonal workers in a post-Brexit world means that “it’s looking pretty bad in terms of the security of the food supply chain. It would be disastrous.”

Of course, embracing the spirit of Brexit to the full would immediately hurt this and other industries. The issue is one facing a number of countries that rely on cheap labour. For example, if Donald Trump got his way and deported illegal immigrants from the US, the Californian economy would probably collapse overnight.

If the pay was more reasonable in this lucrative industry, there would be no labour shortage, regardless of Brexit

But the question of cheap foreign labour raises a number of thorny issues. For example, one popular response is to point the finger at the unemployed. Why are we so reliant on foreigners when thousands of people are sitting around doing nothing? Put them to work in the fields, and if they don’t want to get their hands dirty, tough!

The argument is ridiculous not simply because it plumbs the worst depths of populist idiocy. It misses the point that many unemployed people are elderly or ill, rendering them useless for jobs that require hard labour. But even able-bodied people can’t be forced to do work they don’t want to do. That type of thing only happens in countries that have given up on basic human rights.

It’s here that we enter into tricky territory. We’re against British people being forced to do low-paid work, but completely fine if a desperate Polish mother-of-three ends up doing it instead. Something of a double standard?

Insipid nationalism is a great way to displace the problems of “extreme capitalism” on to a particular ethnicity or minority group. Wasn’t this really what Brexit was about at the end of the day? So, instead of fixating on the worker as such (who they are, where they come from, whether they are taking employment from a British person), we ought to look at the work itself. Especially the pay and conditions. The real travesty in this story are the low wages that have become normal in a lucrative industry. If the pay was more reasonable, there would be no labour shortage, regardless of Brexit.

What’s more, if agriculture is really a question of national security, then why couch it in such degrading economic circumstances? Is it wise to underpay a workforce that the country relies upon for its economic stability? On the other hand, it’s striking how the agricultural industry is cast in these terms whereas water, electricity and transport – all of which have been sold off to overseas investors who only care about their next dividend – isn’t framed in the same way.

We should all be in favour of the free movement of workers because it makes Britain such an interesting and diverse place. But we ought to question the ultra-low wages that some industries use to exploit that mobility. This is not about immigration or ethnicity. It’s about the warped way in which work is valued in our society. It’s like we live in an upside down world. Jobs that are the most vital socially – rubbish collectors, cleaners, care givers, midwives, produce pickers – are economically valued the least.