Shoppers have thrown their weight behind grocers’ price-matching schemes as controversy over Tesco’s Price Promise promotion mounts.

A poll by ICM Research for Retail Week revealed 27% of those surveyed compare prices between supermarkets every week and 57% said price-matching schemes are important in determining where they shop.

The study also revealed 11% of shoppers compare prices monthly, 41% on occasion and 21% said they never check prices.

However, the research revealed that consumers are skeptical over price pledges. Some 45% said they did not trust price claims made by supermarkets.

The study comes as Sainsbury’s has formally made a complaint to the Advertising Standards Authority (ASA) over “misleading” comparisons. Retail Week revealed last week that Sainsbury’s had complained directly to Tesco and that it was likely to bring its case to the advertising watchdog.

The ASA said Sainsbury’s complaint was the only one it had received.

Sainsbury’s chief executive Justin King said comparing its own-label products with Tesco’s is disingenuous as “most of our own label is not comparable”.

Tesco launched its Price Promise promotion earlier this month comparing the prices of branded and own-label products with Asda, Sainsbury’s and Morrisons.

ICM data revealed 45% of respondents claimed price was the most important factor in deciding where to buy their groceries ahead of quality and location.

ICM said: “More than one in two people (57%) claim that price-matching schemes are important in determining where they shop.

“It is particularly important for those aged 25 to 34 who are more likely to be at the family lifestage while the schemes are less likely to have any relevance to older age groups.”