For the 11 weeks to March 29 food sales rose 2.6% down from 4% in the 15 weeks to January 11.
The retailer said that the impact of “no Easter, together with the associated promotional activity”, had reduced the quarterly sales by an estimated 1.7% for food - giving an underlying performance of 6.3%.
Total like-for-like sales were also slightly down growing 6.7% compared to 7% over the Christmas period - while clothing sales fell 0.3% due to a weak performance from its childrenswear collection.
Chief executive Roger Holmes said: “In the current environment, we will ,manage our clothing stock commitments and operating costs more tightly.
“At the same time we will continue investing in long term growth initiatives, rolling-out the successful Simply Food format, reinvigorating financial services and developing our home business.”
Full-year results will be announced on May 20.