Asda, which is owed by US firm Walmart, said the £50m price overhaul was part of a £200m investment in pricing this year.
Barry Williams, chief merchandising officer for food at Asda, said: “It goes without saying that Christmas can be a struggle financially and when you look at the way people have reacted to the sales, it’s more clear than ever that UK shoppers’ priorities are well and truly focused on price.
“With hundreds of products at 50p, we’re even making the Poundshop and Aldi look expensive.”
Broccoli, cabbage, cauliflower, Iceberg lettuce and spring onions are inclued in the 50p price as well as Kingsmill bread, pasta, Heinz soup, WeightWatchers soup, porridge, biscuits, tinned tomatoes and Dairylea Triangles.
Industry figures from Kantar showed that over half of the country shopped in either Aldi or Lidl during the 12 weeks to December 17.
Elsewhere, all of the big four grocers - Tesco, Sainsbury's, Asda and Morrisons - lost market share over the same period.
Asda said the price cuts were funded by its savings programme 'We Operate For Less', as well as the price bargaining power it has with parent company Walmart.
