Worldpanel compiles its monthly snapshot of the UK grocery market by analysing the household grocery purchasing habits of 30,000 British households. The data Worldpanel collates is based on the value of the items purchased by those consumers. Tesco holds a strong advantage as Britainâs largest grocery retailer, with Sainsburyâs, Asda and Morrisons making up the so-called âbig fourâ. However, value players Aldi and Lidl have closed the gap to the established order considerably having grown their respective market shares at a pace following the 2008 financial crisis. The discount duo hope to make further gains in the post-covid-19 recession.Â