Coles has slashed prices for beef steaks and lamb chops by more than 20 per cent following accusations the supermarket giants have not passed on lower prices paid to farmers, amid threats of government intervention into supplier relationships.

The promise of lower prices for three months on more than 300 products, including some meats, deli and seafood, dishwashing tablets and tea bags, came on the same day official inflation data showed price growth had slowed to its lowest rate in almost three years, driven in part by falls for some supermarket staples.