Asda is the first of the big four to declare its Christmas trading performance, claiming it bucked the poor Christmas retail trend with sales above expectations.

Customer numbers were up year-on-year by more than one million to 20 million in the seven days before Christmas. The number of stores taking more than £3m in the week was up 50% year-on-year. Friday 22 December was a record trading day.

"The reinvigoration of our food business with better-quality produce, more premium and organic ranges and the widest choice of local products proved to be the perfect Christmas present for everyone that shopped with us over the festive period," said Andy Bond, president and CEO of Asda.

Sainsbury's, Morrisons and Marks & Spencer are all due to issue trading statements next week, with Tesco's Christmas trading update out on 16 January.

Good performances are expected from Sainsbury's and Morrisons, who should both announce strong like-for-like sales, according to analyst Jonathan Pritchard of Oriel Securities.

And early figures from ACNielsen show food sales in supermarkets up 5% for the four weeks to 23 December. In the week before Christmas Eve food and non food sales were up 6% to £3.5bn.