Today is National Fish and Chip Day across the UK, but households have been warned to stop buying cod from chippies and supermarkets.

The Marine Conservation Society (MCS) updated its Good Fish Guide, which aims to encourage shoppers and businesses to make sustainable choices to help keep fish populations alive, following years of concerns about overfishing threatening the future of the fishing industry.

The guide has now downgraded cod to the lowest possible rating for all UK-caught cod, and recommends that shoppers swap cod for hake instead at both fish and chip shops and supermarkets, as well as restaurants.

At the same time, the chippy industry has been battered by rising costs as well as dwindling supplies of cod, pushing prices ever higher.

The National Federation of Fish Friers has praised fish and chip shops for ‘adapting menus’ and looking to secure the future of the iconic British dish and has also urged chippies to look beyond cod.

Good Fish Guide manager Kerry Lyne said the change is a ‘warning signal’ and called on the Government to ‘address concerns’ to allow cod stocks in British waters to recover.

The Good Fish Guide explains: “The sustainability of Atlantic cod varies a lot, depending on where and how it was caught. Most cod sold in the UK is from Iceland or the Arctic. Avoid cod from the Arctic and North Sea. For the best choices, look for Icelandic cod caught by longline or gillnet. Cod is one of the most popular seafoods in the UK. It is sold in many forms in UK supermarkets, including fresh or frozen fillets, and a wide range of processed products. It is also a staple in fish and chip shops, seafood restaurants, and fishmongers.

“As an alternative to cod, the Good Fish Guide recommends alternatives such as European hake, which is similar to cod but has healthy UK stock levels, as a more sustainable choice for a flaky white fish. Some UK haddock remains a good option, depending on where they are caught – look out for haddock caught in the North Sea or West of Scotland for a good choice.”

Earlier this year, supermarket Waitrose suspended sales of mackerel after conservationists raised an alarm about population levels.

The retailer says it is the first UK supermarket to suspend sourcing of mackerel, which it gets from Scottish waters, with sourcing of fresh, chilled and frozen mackerel suspended by April 29 and tinned mackerel following once the current stock has sold.

The move comes in the wake of failures by governments to cut catches to levels recommended by scientists to ensure sustainable fishing and stop mackerel stocks collapsing.

Conservationists welcomed Waitrose’s move to take mackerel off its shelves, and urged other supermarkets to follow suit.

Overfishing has resulted in depleting mackerel stocks in the north-east Atlantic, with warnings being issued that the species, and the wider fishing industry, could face long-term risks unless countries stick to recommended catch limits.

Gary Lewis, President of NEODA (National Edible Oil Distributors’ Association) who founded National Fish and Chip Day which is today (Friday, June 5), told the National Federation of Fish Friers: “We’re encouraging shops and customers to explore a wider range of fish beyond cod and haddock; from hake to pollock and other responsibly sourced species. By embracing variety, we can support sustainability, reduce pressure on key stocks and ensure that fish and chips remain a staple of British life for generations to come.”

Meanwhile, the Daily Express has launched the Save Our Fish and Chips campaign to help support the sector.

NEODA has added its voice to pleas for a VAT cut to help the struggling industry.