Tesco is now one of the most expensive supermarkets in the country, as it fell back further in the Which? October rankings.
Comparing the cost of 23-item baskets put Britain’s biggest retailer third-last in a table of affordable grocers.
A month earlier, it had tied for fifth with Morrisons on £28.31, but a price rise of 34p pushed it down into sixth.
Aldi (£24.24) and Lidl (£24.97) maintained their gold and silver medal positions.
However, the gap between the discounters and Asda (£25.94) has closed significantly since September.
Sainsbury’s missed out on a podium position on £27.71, while Ocado lagged behind Tesco on £29.95.
Waitrose brought up the rear on £33.81, almost 40 per cent higher than Aldi.
Tesco’s problems were even more acute when Which? analysed a 77-item trolley.
It was already the priciest of the Big 4 in September, but the following month dropped behind Ocado to second-last place on £156.72.
Waitrose, again, fell well behind its competitors with £164.91.
Asda (£143.21) continued its 22-month winning streak, followed by Sainsbury’s (£145.56) and Morrisons (£150.26).
Since the second analysis contained a higher number of branded products, it did not include Aldi or Lidl.