Choice says the initiative will force grocery prices to drop.

It is not the website the federal government offered, and failed to deliver, in a pre-election promise to ease cost-of-living pressures.

It is Choice's version of the controversial price-comparison website, which was scrapped by the government last year.

The government said at the time it was concerned about the accuracy of the information and potential for incorrect prices being listed. Choice says it was dumped because of lack of co-operation from the two major chains.

The non-profit consumer group asks shoppers to look beyond the major two supermarket chains for cheaper groceries.

Consumers will notice if they visit checkoutchoice.com.au that it, too, does not offer shoppers individual prices for items at their local supermarkets or state which store is the cheapest in their area.

Under a ''take action'' category, consumers are asked to join a national campaign to bring competition to the supermarket sector. They are asked if they have noticed any items on supermarket shelves being replaced by the supermarket's own home brand items.

The website also calls for farmers and suppliers to tell any stories they may have about the ''ugly side of market power''. Shoppers can click on ''dob in a price scam'' when advertised pricing does not match the reality.

Choice chief executive Nick Stace tells visitors to the site that in Australia over 75 per cent of all packaged groceries are sold by Woolworths and Coles.

But the Australian Retailers Association, which represents Coles and Woolworths, said the sector had never been more competitive. ''The major supermarkets have worked hard to introduce more price transparency,'' chief executive Margy Osmond said.