Who is going to do the heavy work post-Brexit?

In the past five years only one Briton applied for work as a fruit picker at Tuesley Farm. The pickers start at 7am and work 8 or 9 hours, for £8.50 - £9.50 per hour. They have one day off a week. The Brit lasted a day before deciding the work was too hard and that the other pickers worked too fast.

The number of seasonal agricultural workers coming over to British farms each year has dropped by 17%, and we haven't even left the EU. If the threatened immigration controls come in then a crisis will become a disaster. 70% of Tuesley Farm workers come from Romania, Poland and Bulgaria.

Farmers could manage if that was the only issue. Pay more, expect less: It would mean prices would go up, but if it means keeping out foreigners then surely Brexit supporters would willingly pay.

If only it were that simple. We already have full employment, so any workers attracted to picking will be leaving other jobs unfilled. Meanwhile the Brexiteers justify leaving the EU by talking up free trade. However free trade will mean British farmers being priced out of the market by cheap imports - they won't be able to afford to pay pickers more. Boris Johnson may want to have his cake and eat it, but its ingredients won't be grown in Britain.

Mr Gauke, the justice secretary, has suggested one possible solution - letting criminals out of prison to do work in construction, catering and agriculture. Quite how they would be managed is hard to imagine - in the USA 'chain-gang' prisoners are literally chained together and their guards carry heavy rifles. We barely have enough prison officers as it is, and they don't carry weapons. Maybe Mr Gauke is thinking of asking convicted gang bosses to keep an eye on things? Interestingly, Mr Gauke says that it is inevitable that the prisoners will commit more crimes while on release - it is not clear that their prospective employers would be similarly relaxed about this.

This brilliant idea is possibly even worse than the clever wheeze Ms Leadsom borrowed from revolutionary China.

No wonder the owner of Tuesley Farm now regrets voting for Brexit.