Consumer groups, MPs and price comparison websites have thrown their weight behind a bill put together by a top Southampton politician.

John Denham, MP for Southampton Itchen, is calling for shoppers to be given instant online access to supermarket prices across different stores, after revealing details of “misleading deals” and “dubious pricing strategies” from supermarkets.

Included in the dossier is Tesco’s Big Price Drop campaign, which found that every two items that were dropped in price, three products became more expensive.

Mr Denham said: “In tough times, when living standards are falling, shoppers need every help to get the best value for money.

“My Bill will even up the relationship between supermarkets and the consumer.

“Supermarkets collect and analyse data on shopping habits to shape their pricing and promotion policies. Yet many consumers are still left shopping around from store to store to get the best deal in much the same way they did decades ago.

“Consumers will quickly be able to compare the price of their shop to get value for money. The release of this data will put an end to misleading pricing practices and dodgy deals. “They will also be able to see where branches of the same supermarket charge significantly different prices.”

Consumer champions Which? and price comparison website MySupermarket are among those backing Mr Denham’s bill.