In London and Birmingham a bag of fish and chips is about £6 while in Kent a large cod and chips costs more than £5.Dwindling cod supplies and rocketing potato prices are blamed for the increase.
Chip shop owners say they are struggling to keep prices down while still providing value for money.
Ijaz Akhter, owner of Viking Fish and Chips, in Watford, said: “We are having to put prices up as the cost of potatoes has risen considerably in the past five months and it is expected to go up further.”
Potato production costs soared from £124 a ton in November 2011 to £200 a ton last autumn after crops were ruined by torrential rain.
Michael Pili, training manager with the Midlands Seafish Industry Training Association, said shops also faced higher water, fuel and insurance costs.
But he added: “The industry is 151 years old and has survived world wars, recessions, power cuts, three-day weeks, shortages and the Cod War.”
