Asda has long been known as the UK’s cheapest supermarket, but research carried out for The Grocer shows that it is also the most trusted on its claims about price and promotions.

A survey of 1,200 shoppers carried out by customer loyalty specialists Satmetrix found Asda outperformed all of its rivals in terms of trust among shoppers.

Just over a fifth (20.1%) viewed the Leeds-based retailer as the most trusted for representing prices and offers accurately. This was higher than second-placed Sainsbury’s (14.9%) and also higher than its own 17.2% current market share [Kantar Worldpanel 12 w/e 25 December 2011].

Of the major retailers, M&S pulled in the fewest votes, with just 5.3% rating it the most trusted, while 11.8% thought market leader Tesco was and only 8.1% felt that way about Waitrose.

“When you are who you say you are it unlocks the key to real customer loyalty,” said an Asda spokeswoman. “That’s not about plastic and points, it’s about us delivering on price, quality and service.”

Uncertainty around the value of retailer promotions has been headline news recently, following a Panorama investigation last month. Satmetrix MD Robert Salvoni said failing to deliver genuine deals could seriously affect shopper loyalty.

“The experience consumers have every time they visit a supermarket conditions loyalty levels and the conversations they have with their family and friends,” he said.