Tesco has recorded its strongest performance in 18 months with a sales increase of 1.1% in the 12 weeks ending 1 March 2015, according to new figures from Kantar Worldpanel.

The grocery multiple was the standout performer of the big four, with Asda’s sales down 2.1% and Morrisons and Sainsbury’s posting a sales dip of 0.4% and 0.5% respectively.

Aldi continues to grow well ahead of the market with sales up 19.3% compared with a year ago, even if it was its slowest rate of growth since June 2011, but it was enough to take the discounter to a record market share of 5.0%. Lidl’s sales grew 13.6%, increasing its share to 3.5%.

The figures also show that grocery inflation has reached a new low of -1.6% as price competition between the supermarkets continues to impact the market.

Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel, said: “A combination of lower general inflation and the grocery price war has saved shoppers £400 million in the past 12 weeks, with deflation driven to a record low of -1.6%.

“All of the major supermarkets are cutting prices to win shoppers, especially within everyday staples such as eggs, vegetables and milk. Retailers are focusing their efforts on simple price cuts rather than complicated ‘multibuy’ deals.”