Tesco has experienced the fastest sales growth in the UK when compared to the other "Big Four" supermarket chains, namely Morrisons, Sainsbury's, and Asda, within the nation.

Data from the company Nielsen has revealed that Tesco's sales increased by 2.2% during the 12 weeks ending May 20. The supermarket chain was also able to maintain its grasp over the market, with the largest grocery market spend by retailer value of 27.2%.

During the same period, Morrisons' and Sainsbury's sales increased by 1.4% and 1.2% respectively, while Asda's sales declined by 0.1%.

Aldi and Lidl are quickly emerging as strong competitors, with respective sales growth of 18.1% and 19.7% indicating their potential to challenge the established Big Four order. Aldi's current grocery market spend by retailer is 8.1%, while that of Lidl is 5.4%.

"Tesco's re-focus on the customer and their changing needs, such as simplifying ranges and promotions, has meant they've not only attracted new shoppers but encouraged them to visit more often," remarked Mike Watkins, Nielsen's UK head of retailer and business insight.

"These incremental improvements are helping reverse the declining spend per visit which was an ongoing challenge for Tesco last year. The growth is also now being supported by initiatives which revisit some wider consumer trends such as tackling food waste and supporting healthier eating and living."