Supermarket growth has stalled at 0.9 per cent as the retail price war continues to pressure the sector.
Kantar Worldpanel data for the 12 weeks to September 13 showed revenue growth was well below the 20-year average of 4 per cent.
The consumer insight body said the growth of the discount retail sector continued to affect the whole sector and growth in volumes failed to offset lower spending.
Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel, said: "This is the sixth month in a row growth has been less than 1 per cent. We are seeing modest volume growth but not enough to offset lower prices."
Tesco’s overall sales fell by 1 per cent and its market share dropped 0.6 per cent to 28.2 per cent. Morrisons sales decreased by 1.7 per cent as its market share fell to 10.7 per cent.
Kantar said this fall was likely to continue with the closure of Morrisons convenience outlets. Asda remained the UK’s second largest supermarket despite its share falling to 16.7 per cent. Sales were down 2.9 per cent compared to a year ago.
Lidl’s sales grew 16 per cent as its market share rose to a high of 4.2 per cent. Aldi grew sales 17.3 per cent and now commands 5.6 per cent.
Mr McKevitt said: “With shoppers moving their custom away from the traditional, larger-size supermarket stores, online sales are continuing to boom and are up by 12 per cent compared with a year ago.
"Almost 7 per cent of grocery sales are currently purchased through the Internet and existing online supermarkets will be watching closely to see when Amazon Fresh will launch in the UK and whether it will steal market share or grow the online market even further.”