Tesco and Asda have slammed an Early Day Motion calling for all supermarkets to publish detailed price lists.
The EDM, tabled by Tom Watson MP, calls for legislation "to oblige large retailers to publish weekly price lists of all their stock in a standard, machine-readable, open digital format".
It follows a recent investigation by The Guardian into price cuts by the retailers, which claimed that the majority were only 1p (see also The Grocer, 7 March 2009).
The EDM "deplores the behaviour of retailers who seek to manipulate prices in this cynical way". As The Grocer went to press, it had 44 signatures.
Both Asda and Tesco's prices are already freely available on their websites and home shopping catalogues.
"There surely can't be a clearer, more standardised, machine readable, open digital format or are we missing something?" an Asda spokesman said. "We look forward to the day when every MP's expenses are as equally open and easy to read on the web."
Tesco has written to signatory MPs to point out it had cut the price of 2,500 products in the run-up to Christmas, with an average price cut of 54p.
Editor's Comment: We need cuts and Sir Don Curry can do it (6 March 2010)
Up to half the lines in latest 'Rollback' offer just 1p saving (7 March 2009)