Asda has suffered its sharpest quarterly sales decline in its history with like-for-like sales down 7.5%.

The supermarket said “fierce competition and food deflation” had fuelled the decline in sales over the three months leading to 31 July, during which time Sean Clarke took over as CEO.

Asda has now suffered eight consecutive quarterly declines and was singled out by Walmart International CEO David Cheesewright for its “very disappointing” performance in June. Walmart’s international division posted a 6.6% decline in sales despite nine out of 11 of its international markets announcing sales increases.

Cheesewright’s suggestion to “shift the balance from protecting profit to protecting share” was expected to result in Asda triggering the start of a price war today, but it made no mention of a change in strategy.

“Our strategy to turn things around is focused on improving the retail basics. We are simplifying and strengthening our offering through improved availability and assortment discipline, reducing costs and driving sales through strategic price investments,” said Walmart Stores CEO Doug McMillon.

“While our turnaround will take time, I’m confident in the new leadership team there and want to assure you we’re addressing this with urgency.”

Paul Thomas, senior consultant at Retail Remedy retail consultants, said it “could be no worse” for Asda. “It is too soon for the new CEO to have had any significant impact but a 7.5% decline in like-for-like sales is apocalyptic for Asda,” he suggested. “There is absolutely no honeymoon period for Sean Clarke: it’s a case of get in there and power up the defibrillator.”