Raymond Blanc, renowned chef and ambassador of the Sustainable Fish City campaign, said: “We are delighted to see towns and cities running Fish City campaigns, and supporting a responsible approach to buying fish. By coming together, we have the buying power to transform the way fish is bought and sold in the places where there is a huge demand for fish.”

So far, 12 towns, cities and counties feeding more than 13 million people have confirmed that they are working towards becoming a Sustainable Fish City. These include: Belfast, Bournemouth & Poole, Brighton & Hove, Bristol, Cardiff, Newcastle, Hull, Lancashire, Liverpool, London, Plymouth and Stockport.

They are members of the Sustainable Food Cities network, a new collaborative approach to tackling food issues across towns, cities and counties. Each area will now work to generate the support of local schools, universities, hospitals, businesses and restaurants – asking them to sign up to a fully sustainable fish policy.

Campaign co-ordinator Ruth Westcott said: “It is inspiring to see so many towns and cities taking up this challenge. It shows how important this issue is to people across the UK. We don’t want to be contributing to the loss of our precious marine ecosystems when we eat out, and I am delighted to see so many businesses, as well as places, joining in, to take a stand on this vitally important issue.

“We estimate that together, these areas spend more than £700m on fish every year, which could be supporting our sustainable fisheries.”

Businesses and organisations serving in excess of 200 million meals per year have already come forward to pledge their support for the campaign, including central government for prisons, government departments and the armed forces, 19 universities, the National Trust, John Lewis, Carluccio’s, Brasserie Blanc, Michelin-starred restaurants and independents.

Many large contract caterers have also committed to switch to sustainable fish for all their catering. Following in the sustainable fish footsteps of the London 2012 Olympic and Paralympic Games, visitors to the Glasgow 2014 Commonwealth Games will only be served sustainable fish after the Commonweath Games committed to a fully sustainable fish policy.

Restaurants and caterers can support the campaign in their area by signing the online fish city pledge, and take advantage of expert advice and promotional materials to help improve the sustainability of their seafood menus. Local people can get involved by asking the places where they eat out – restaurants, canteens and sandwich shops – to sign up to a fully sustainable fish policy.