Bertrand Hourdel proudly pats one of his plump pigs, but the Brittany farmer is painfully aware that when he sells them, his profits, if any, will be slim.

He blames the European Union’s “straitjacket” of regulations and inaction by politicians from establishment parties for French farming’s deepest crisis since the Second World War.

Brittany’s verdant pastures and ancient stone farmhouses are a picture of bucolic bliss, but anger and desperation in France’s leading agricultural region, and other rural areas, are shifting the political winds in favour of Marine Le Pen’s anti-EU Front National.

“If France left the EU, I hope things would get better,” said Mr Hourdel as he watched pregnant sows bedding down on straw.

France remains the biggest beneficiary of EU farm aid, but more than a third of French farmers earned less than €4,200 (£3,560) last year, squeezed by falling food prices and cheaper imports from other member states.