We believe that British eggs are now the safest in the world

British Eggs Industry Council

New schemes to stamp out the dangerous bug have led to a big fall in cases and retailers believe they now have the problem cracked.

Tesco say independent tests show no traces of the bug have been detected in its eggs for 18 months - thanks to a vaccination programme.

And Sainsbury's say a new technique to be introduced shortly will guarantee that eggs of the future will be salmonella-free.

Efforts to beat the bug have been stepped up since the late 1980s, when a scare over the bug, sparked by Tory health minister Edwina Currie, rocked consumer confidence.

The Lion scheme vaccinates hens against the bug

Tesco said its breakthrough was a "triumph" for the supermarket's programme to vaccinate all laying hens against salmonella, with attention now turning to wiping out traces of the bug in chickens.

Steve Murrells, Tesco meat and poultry category director, said: "We've now cracked it on eggs and we've got record lows on fresh poultry. The challenge now is to eradicate salmonella across the board."

A spokeswoman for Sainsbury's said it was impossible for the supermarket to test every egg, but that a new process would soon destroy the bug forever.

She said: "Now we've gone one step further. We've developed a technique where we can pasteurise our eggs in their shells without cooking them which will guarantee them to be free from salmonella. We are hoping this comes into practice very shortly.

"However, all the eggs in our store are laid by hens vaccinated against salmonella, highlighted by the fact that we have the Lion Quality, given by the British Eggs Council."

Council chairman Andrew Parker, referring to the big fall in salmonella cases, said: "We believe that British eggs are now the safest in the world."