While Aldi achieved a record high market share of 4.9 per cent, and saw sales rocket 25.5 per cent higher than last year and Lidl's 16.8 per cent boost in sales brought its market share to 3.5 per cent, Sainsbury's and Morrisons both recorded a decline in share compared with last year with sales down 2.5 per cent and 3.3 per cent respectively. Asda recorded the best performance among the big four and held its 17.2 per cent market share. Tesco's sales suffered the greatest drop, down by 3.7 per cent, however the rate at which it is losing market share has slowed. Meanwhile, Waitrose has grown sales by 5.6 per cent to take a 5.1 per cent share of the market. Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel said the declining grocery market is of particular concern to retailers in the lead up to the Christmas trading period.