The Co-operative Group has returned to growth for the first time in a year, the latest grocery share figures from Kantar Worldpanel have revealed.

For the 12 weeks ending 19 July sales were up by 1% and shopper numbers increased by 133,000. Meanwhile, the overall market has seen a growth of 0.8% compared with this time last year.

Despite a fall in sales of 0.3%, Sainsbury’s edged its market share up to 16.5%, overtaking Asda in the process. This has returned it to its position as the second largest supermarket for the first time since January. This has been boosted by non-food sales, its Local outlets and growth in south of the country.

Growth has accelerated at Waitrose, where sales have risen by 3%. Customers have taken advantage of the recently introduced ‘Pick Your Own Offers’ initiative to push market share up to 5%, an increase of 0.1 percentage points compared with last year.

Sales also rose 3% at Iceland, helped by its recent ‘Power of Frozen’ advertising campaign.

Aldi grew by 16.6% while Lidl saw growth of 11.3%, meaning both have moved to market shares of 5.6% and 4.0% respectively.

Morrisons was the best performer among the ‘big four’ retailers, although sales fell back by 0.1%. Meanwhile, sales at Tesco fell by 0.6% and at Asda by 2.7%.

Fraser McKevitt, head of consumer and retail insight at Kantar Worldpanel explained that the continued slow growth of the overall market can be explained by minimal volume growth and lower like-for-like prices.

“Comparable groceries are now 1.6% cheaper than a year ago, meaning prices have been falling since September 2014, although they are projected to start rising again by early 2016,” he said.

An Asda Spokesperson said: “We’re going through one of the toughest trading periods to face UK supermarkets, so it comes as no surprise that industry figures continue to be volatile from month to month. As a strong and balanced business we remain focused on our long term strategy for building a sustainable business over the coming years.  We won’t make knee jerk decisions because of the short-term picture.”