“Of all the electricity, gas and wages costs, none of them, zero, have been passed on to customers,” Bérangère Michel, its finance chief, said.
A closer look at the figures, however, shows the mutual, which also owns John Lewis department stores, has been less effective in keeping prices down at Waitrose at a time when cash-strapped shoppers are hunting for bargains.
The supermarket's cost price inflation reached 8pc by the end of July and “has since continued to rise”, the mutual said on Thursday, albeit this is still lower than the overall inflation rate of 12.4pc recorded in August by Kantar.
All the Big Four chains were cheaper than Waitrose, according to the Grocer’s weekly mystery shopping service last week.
Waitrose’s basket was considerably more expensive at ￡73.13, coming in more than 20pc higher than Asda at ￡59.64. A total of 33 products – spanning both branded and private label – were tracked.
Meanwhile, prices for everyday staples have gone up by more than 30pc in some cases, according to data from Trolley.co.uk.
Two pints of Essential semi-skimmed milk costs ￡1.20, an increase of 33pc year-on-year, for instance. The price of a can of Heinz Baked Beans has jumped 50.4pc to ￡1.85.
Some industry observers believe that Waitrose hasn’t acted quickly enough to lower prices while rivals have been launching aggressive price-cutting campaigns.
“Staying relatively quiet in the face of the cost-of-living crisis for much of the year has come at a cost,” Amira Freyer-Elgendy, a retail analyst at GlobalData, says.
She expects more Waitrose shoppers to defect to the discounters or Tesco for everyday staples and household goods as a result, a trend that is already relatively pronounced.
Basket sizes were nearly a fifth smaller during the period compared to last year, Waitrose admitted, despite transactions being up 14pc year-on-year.
“Waitrose will therefore need to justify price points across its full range, carefully market its Essentials label to showcase value and affordability, and encourage dwell time to protect basket sizes from further erosion,” Freyer-Elgendy adds.
James Bailey, the boss of Waitrose, said: “We are hopeful that [food] inflation is running out of steam, but there is still a lot of structural stuff coming through in terms of crop cycles.
“How and when we choose to pass that on to consumers, we’re exceptionally careful [about] and we do an awful lot of work with our supply base.”
