It is Wimbledon fortnight and England’s proliferating band of commercial winemakers are praying for continued good weather. If rain interrupts the gurning and grunting on the outer courts it will also reduce the number of vine flowers that fructify into grapes. But if the weather stays dry, yields and profits will soar – bolstering an activity that global warming is turning from a hobby into a serious business.

“The first flowering coincided with the first tennis match,” reports Michael Roberts, from his Ridgeview winery in Sussex. Optimism is tempered by experience: “So far so good, as the man who jumped off the Empire State Building said, passing the 41st floor,” he says. Cold, wet summers in 2007 and 2008 depressed English wine production. At about 2.5m bottles annually, this remains a mere drop in the European Union’s wine lake. But the trend is expansionary. English vineyards have grown 45 per cent in area over four years to occupy more than 1,000 hectares. The sight of a chunk of the Médoc transplanted to the environs of Crawley is becoming less incongruous.