Owners say holidaymakers this summer can expect to be charged more, not least because farmers are up to four weeks behind schedule.
Rob Clayton, of the Agriculture and Horticulture Development Board, said: “If we were to get a couple of months of warm and sunny weather the problem would go away.
“If it’s dull and cool that would retard the development. That is when you would start to worry.
“If you’re going to Blackpool in August, that’s when you might be expecting a bit of a pinch around chip shop prices.”
Other pressures were outlined by president of the National Federation of Fish Friers Andrew Crook, who said: “I’ve had to hold price increases back so I’m taking quite a hit.”
Cod and chips at his shop in Lancashire costs £5.90 but the price is going up.
He added: “I think summer’s a good time to put prices up.
“People go on holiday, buy fish and chips and see that some areas are more expensive than back home.”
The fall in the value of the pound together with cuts in quotas means it is 15 to 20 per cent more expensive to import frozen fish.
Six months ago, a kilo of haddock frozen at sea cost around £4 and cod £5.20.
Now, haddock costs about £5.60 and cod almost £5.80.
There is also pressure to replace polystyrene cartons with compostable alternatives, made in China, that cost five times as much.
Mr Crook said: “We have been worried for the last 30 years because we’ve had McDonald’s come in and lots of ethnic cuisines.”
Online delivery firms like Deliveroo and Just Eat are a new threat because other takeaways can make multiple deliveries on one round trip that would make fish and chips deteriorate.
Mr Crook said: “You’ve got to keep fish and chips crisp.
“You can’t do five deliveries and come back.
“You’ve got to do each one individually and the margins are not there for that.”
PRICES AT A TYPICAL CENTRAL LONDON FISH AND CHIP SHOP
Cod fillet (Regular) – £7.60
Cod fillet (Small) – £4.90
Haddock fillet – £7.20
Popcorn cod and chips – £6.10
Plaice fillet – £8.10
Skate – £9.30
Rock salmon (Huss) – £9.50
Whole plaice – £11.30
Salmon – £14.00