Bad weather has affected vineyards in the UK and France this year but English sparkling wine producers have got off more lightly than their Champagne counterparts - and that could give them a competitive edge.

Frost, hail, rain and grape rot are expected to have taken a heavy toll on Champagne yields when the harvest begins next month. Although English vineyards predicted a slight reduction in crop after this year’s heavy rains, they remained optimistic about the harvest.

“It’s a horrendous situation for the growers in Champagne,” said Sam Lindo, winemaker at Cornwall-based Camel Valley. “We’re a little bit below average, but we never hit the average, we’re either way below it or way above it.

“Until the grapes are fully formed and the bunches have closed you don’t really know what yield you’ll get, but we’ve got grapes on the vines and we’re happy.”

The changeable weather will result in a slightly later start to the harvest for Camel Valley and other English vineyards including Denbies, which expected yields to be 25% lower than a particularly strong harvest.

“The fruit hasn’t set as well as we’d hoped, which will affect the quantity, but we are still hoping for a very good-quality year because of the higher concentration of nutrients going into fewer grapes,” said Denbies MD Chris White.

Champagne’s lower yield was likely to push up its prices in a few years and reinforce the competitiveness of English sparkling, he added. “The quality is there so if we can keep prices comparable or lower to what they’re producing it’ll be really exciting.”

The Diamond Jubilee and Olympics have prompted sales uplifts for both vineyards, with Camel Valley reporting a 20% rise in demand and Denbies boosting orders by about £500,000.