Campaigning organisation Greenpeace has accused supermarket giant Tesco of stocking a brand of tuna that is caught in a way that can harm other wildlife.

This is despite a pledge in 2012 to ensure all its own brand tuna was sustainably caught. In addition - after the horsemeat scandal - the supermarket promised to be more open and transparent on the origins of all its produce.

Now, says Greenpeace, Tesco has started to stock tinned shredded tuna flakes in brine from low-cost brand Oriental and Pacific (O&P). This fish is caught in large nets.

LDH, a joint British-Italian company whose major shareholder is the Italian La Doria company, owns the O&P tuna brand.

It admits that O&P brand skipjack tuna is caught using the purse seine fishing method which, Greenpeace says, can also kill other marine creatures such as turtles, rays and sharks.

In reality the new product hasn't done Tesco any favours. Many of its customers, temped by the very low price of the new brand, have been disappointed and told consumer websites and Facebook pages that the shredded tuna is more like cat or dog food and has a nasty smell.

In a comparison of the sustainability of various supermarket tinned tuna the Greenpeace said Sainsbury's was leading the way.

Waitrose, the Co-operative, Marks and Spencer and Morrisons were also praised.

Ariana Densham, Greenpeace UK Oceans campaigner, says: "Morrisons joins Sainsbury's as a market leader on tuna sustainability.

"They have eliminated unsustainable tuna from their products, which is great news for sharks, turtles and rays.

"If Tesco wants to catch up with the front-runners and win back consumer confidence, they must take this dirty tuna off their shelves today."

Food campaigner and celebrity chef Hugh Fearnley-Whittingstall featured the subject on his Channel 4 Fish Fight programme.

He too called on Tesco to take the brand off its shelves.

Previously, Tesco had said it had moved much faster than many of its competitors to ensure its own-brand tuna was caught entirely using a pole and line - a method which avoids catching other species by accident.

It had also promised to use sustainable tuna in other products such as pastas, sandwiches and salads.

Tesco has long dominated the country's high streets and out-of-town shopping centres to such an extent that more than a hundred organisations, from Friends of the Earth to the Women's Institute, have now called on the supermarket giant to be curbed.

Up and down the country it has been rightly blamed for the dwindling number of independent butchers, grocers and corner shops and the decline of town and village high streets. Today it is also Britain's biggest fishmonger.

This domination of the market place has made it very unpopular, indeed hated and Tesco had been fighting back to polish its tarnished name.

After the horsemeat scandal it seemed it was trying hard to rebuild its damaged reputation. Now it seems, in the scrabble for profits and an even bigger share of the market, it is back to its bad old ways again.