Sainsbury's reported a 15% increase in online orders over the Christmas period, while online sales grew almost 10% for the 15 weeks to 9 January.

The grocer also reported a record week delivering 289,000 orders during the quarter, while it increased its click & collect sites to 101 and opened 16 new convenience stores.

But in-store trading was not as strong, with like-for-like retail sales dipping 0.4%. The grocer reported 30 million customer transactions in the seven days before Christmas (up 2.6% year-on-year), while 24 December turned out to be the biggest day ever for convenience sales as customers rushed to buy last minute items.

Mike Coupe, chief executive, said: "We have traded well during the festive period in a highly competitive market. Our stores delivered excellent levels of service and availability and we launched several new seasonal products and range improvements. As a result we have seen our market share grow in the quarter.

"We reduced our levels of vouchering and promotional participation year-on-year," he added. "We also reduced the number of multi-buys in favour of lower regular prices, continuing our commitment to simplify prices and promotions. Our continued investment in quality, price and service drove like-for-like transaction and volume growth year-on-year. "

George Scott, senior consultant at Conlumino, said the grocer's festive performance overall was very disappointing. "Its core food positioning is arguably better balanced than the rest of the Big Four, and it is quick to highlight sales volume growth as evidence that its strategy is working, like its rivals. The reality though is that its product and price investments, together with its strong non-food trading are currently not enough to fight the winds of food deflation and price competition. We still retain a positive view that Sainsbury’s brand values around affordable quality will eventually bear fruit, but its sales growth will take time to recover."