Supermarket Sainsbury's has warned the market is growing at its slowest pace for nearly a decade as it broke a nine-year run of underlying sales growth.
The group revealed that like-for-like sales excluding fuel slumped 3.1% in the 10 weeks to March 15, marking a sharp reversal of recent fortunes and the first fall after 36 consecutive quarters of rising sales in a row.
Outgoing boss Justin King said the group came up against tough comparatives from a year earlier when it outperformed many rivals amid the horsemeat scandal and benefited from the timing of Mother's Day and Easter trade.
But he stressed that the market was facing tough conditions in the latest downbeat trading statement from one of the "big four" players as cost-conscious consumers increasingly turn to discounters such as Aldi and Lidl.
He said: "The market is now growing at its slowest rate since 2005, with falling food inflation in particular benefiting customers."
He added: "Although some economic indicators are showing an improvement in the health of the economy, we expect the outlook for customers to continue to be challenging for the coming year."