Tesco has committed to sourcing 100% pole-and- line caught tuna by the end of 2012 ahead of a new TV showdown with its old adversary Hugh Fearnley-Whittingstall.

Hugh's Fish Fight debuts on Tuesday on Channel 4. In the three-part series he criticises Tesco over its claim to use responsible fishing methods to catch the tuna in its own-label cans. In the programme, he reads a label on a can, which states: "Tesco is fully committed to fishing methods which protect the marine environment and its species." He questions its "consistency or indeed validity" while Greenpeace's Willie McKenzie describes the statement as "bluewash."

Fearnley-Whittingstall then writes to Tesco, asking them to meet him. "Just imagine this [letter] arriving at Tesco towers they're not going to be pleased, are they?" he says, adding "... they're going to go 'oh it's him again'."

Tesco confirmed it did meet with the chef but a spokesman claimed it had been "moving in this direction for some time".