Almost 50% of UK grocery shoppers are now visiting Aldi or Lidl every month as the discounters continue to gain market share at the expense of the multiples, according to new research from Nielsen.

Aldi’s market share rose to 6.4% in the 12 weeks to 12 September 2015, up from 5.1% in the same period in 2014, while Lidl’s market share increased from 3.6% to 4.3% over the same period. Together they account for 10.7% of UK supermarket sales.

Separate data released by HIM International found that 80% of Germans visit discounters for their grocery shopping, highlighting the potential dominance of German discounters Aldi and Lidl in the UK.

Mike Watkins, Nielsen’s head of retailer and business insight, said the discounters were set to gain market share over Christmas.

“These discounters are attracting new shoppers by opening new stores and using ads that communicate not just value, but quality and freshness too,” he said.

“Discounters now attract nearly one in two shoppers every four weeks and look set to gain significant increases in market share for the third consecutive Christmas, as they become a bigger part of shoppers’ Christmas repertoire.”

Sainsbury’s was, once again, the best performing of the big four, and the only one to record a year-on-year increase in sales (0.1%). Asda was the worst performer with a -3.7% decline in sales compared to the previous year.

Elsewhere Waitrose and Marks and Spencer recorded a 3.4% and 2.8% sales increase respectively.