Up to one third of French wine production will be lost this year as a result of freezing temperatures, according to reports.

It is estimated £1.7 billion in sales will be lost this year after an unseasonal bout of frost and ice followed a period of warm weather, which exasperated the damage. Experts said the warmth encouraged vines to develop earlier in the season than usual, which meant the subsequent plummeting temperatures worsened the damage.

Winemakers in Bordeaux, Burgundy, Provence and the Rhone Valley have all reported damage to vines. Many battled to save vineyards by lighting candles near vines and trees during the colder nights.

Thomas Montagne, the head of the European confederation of independent winegrowers, said: “There is a sense of disillusionment here because French wine producers had already been hit hard by Covid lockdowns and bar and restaurant closures. Independent producers were hit hard by the cancellation of wine fairs due to Covid. International exports have also been affected; we were already hit by the tariffs on French wine imposed by the former US president Donald Trump.”

The French wine-trade news site Vitisphere reported temperatures below zero in large parts of France for three nights in a row from April 6, with temperatures dropping to -9C in some areas.

The Rhone Valley has been particularly hard hit, according to reports, especially the Cote-Rotie. Philippe Pellaton, president of Inter-Rhone, predicted the region was heading for its smallest harvest in 40 years with some estates losing their entire crop.

The 2021 frosts are expected to be at least as severe as those of 2017 and 1991 in France, while Italy has also been hit with cold temperatures, reflective of its frost-damaged year of 2003.

In Veneto in northern Italy temperatures went from 27C down to -5C in early April. Barolo producers also reported vine damage from the plummeting temperatures.