The powerful Bordeaux et Bordeaux supérieur wine union has voted to block bulk sales of wine when prices fall below EUR1,000 (US$1,178) a barrel.

The union would withhold AOC certificates from producers who do not sell their barrels to traders at this minimum price. Without the certificate, the wine is relegated to vin de table.

A first in France, the measure has been designed to check a steep decline in prices of Bordeaux wine. The union said it would issue certificates only when presented with a contract signed by the producer, trader and Bordeaux wine trade federation, the CIVB, showing that a barrel cost EUR1,000.

A traders' union has cast doubt on the measure, arguing that it would only buy at EUR1,000 if they could find a market for it but has ruled out legal action.