The most recent analysis of 11 restaurant and pub chains carried out by the two organisations revealed five that failed to meet their minimum expectations - worst was Wasabi, followed by Slug & Lettuce, Little Chef, Giraffe and Yates. All five received unwelcome “Red Fish” ratings.

The most responsible chain in the “Blue Fish” group was named as Jamie’s Italian, closely followed by Brasserie Blanc, Loch Fyne, Las Iguanas and Strada, with TGI Fridays also passing the sustainability test.

Fish2fork and MCS rates the chains according to how they source the seafood they serve and provide information to customers. More than a third of those assessed in the past two years have failed to meet their standards.

“It’s fantastic to see the work restaurants like Jamie’s Italian and several others are putting into seeking out sustainable seafood,” said Tim Glover, managing director of Fish2fork.

“It’s not easy to ensure seafood is responsibly sourced, but it’s vital for the health of our seas, and worth every penny invested by restaurants.”

King and other tropical prawns were identified as among the most problematic types of seafood in terms of sourcing and transparency of information.

MCS and Fish2fork say they are working to ensure that all seafood eaten or traded in the UK is from well-managed fisheries and farms that have as little impact on the marine eco-system as possible.

Diver-diners can post up their own reviews using DinerRatings via fish2fork.com or on the free MCS Good Fish Guide iPhone or Android app.

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