Wine consultant Jacques Boissenot has warned that grapes in Bordeaux may need to be picked before they are fully mature if no rain falls in the region by September 10th.

Decanter.com reports that Mr Boissenot, who advises 180 properties in Bordeaux including the chateaux Lafite Rothschild, Margaux, Ducru Beaucaillou and Latour, said Merlots are particularly at risk because they have already suffered from uneven flowering.

Due to the dry conditions, the expert advised that it may be better for some chateaux to harvest early, rather than risk rot and dilution from rain later in the month.

However, not all vintners are troubled by this prospect: at Chateau Haut Bailly, Veronique Sanders said the Cabernets are in "great shape", while Eric d'Aramon of Chateau Figeac agreed that "this could be a year for Cabernet".

Cabernet Sauvignon is beloved by vintners for its tough skin, which makes it resistant to disease and sudden changes in climate, while Merlot is somewhat more susceptible to damage, rot and coulure.