Asda claims to have ‘pretty significant war chest’ but analyst says it is unclear if it can commit to months of cuts

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More than £3.5bn has been wiped off the value of Tesco, Sainsbury’s and Marks & Spencer’s stock since Friday amid fears that rival Asda will step up the grocery price war.

Tesco, the UK’s biggest supermarket, took the biggest hit; its share price was down 10% by lunchtime on Monday, while second-place Sainsbury’s was down about 8% and Marks & Spencer 7%.