The heads of Bordeaux’s winemaking syndicates are demanding a 20 per cent cut in production to offset falling sales.

The slump is a consequence of shifting habits in France, where drinkers are abandoning claret in favour of rosé, and of difficulties in export markets, notably the UK, the US, and Hong Kong.

“Bordeaux has witnessed an unprecedented crisis in recent months,” said Bernard Farges, chairman of the Interprofessional Committee of Bordeaux Wines, which represents the region’s 5,800 vineyards. Sales in the 12 months to July had fallen by 12 per cent in volume and by 4 per cent in value compared with the same period the previous year, he added.

Mr Farges said Bordeaux vineyards, which have produced an average of 5.1 million hectolitres of wine over the past decade, needed to regulate supply. “We can’t carry on producing five million hectolitres and only selling four million unless we consider that the law of the jungle is our project.” A hectolitre is 100 litres and most bottles are 75cl.

Marc Médeville, chairman of the Union of Bordeaux Wines, issued a similar alert to vineyards: “We should be aware that about a third of production doesn’t have an outlet at the moment. It is imperative that we balance supply and demand.”

“Bordeaux has witnessed an unprecedented crisis in recent months.”

Last year Bordeaux’s winemakers sold 626 million bottles, which represented a 4 per cent increase over the previous year. The rise was largely attributable to export success, notably in Hong Kong, which bought claret worth $363 million. There were also significant increases in sales to the US, which bought $310 million and to the UK, where imports totalled $250 million. However, Bordeaux registered a 7 per cent fall in sales in France last year compared with 2017. The fall appears to have continued in France this year but is not being compensated by exports.

Bordeaux’s wine merchants say they have been hit by the political turmoil in Hong Kong, by a 25 per cent increase in wine tariffs in the US, an economic slowdown in China and uncertainties in the UK over Brexit.

The Union of Bordeaux Wines has put forward two proposals designed to reduce production. The first is to pay vineyards to tear up their wines. The second is to give them a subsidy of $44 per hectolitre to sell their produce as cheap table wine that would not even mention that it came from Bordeaux on the label.