Retailers including John Lewis, M&S, Next, Sainsbury’s, JD Sports Fashion are to reveal key Christmas trading updates this week which will be seen as key indicators to how successful the festive period was for the retail sector.

John Lewis will update tomorrow and is expected to reveal sales in the last week of 2009 rose nearly a third on last year. M&S is expected to say on Wednesday that sales over Christmas rose for the first time in two years.

Christmas sales are forecast to have risen 1% for the retailer in the 13 weeks to December 26 compared to a fall of 7% for the same period last year.

Next said in November that it expected sales in its second half, which ended on Christmas Eve, to be between flat and 3%. It will update the City on Wednesday with Sainsbury’s and JD updating on Thursday.

Online grocery Ocado was one of the first retailers to update on its Christmas performance with like-for-like sales in the week to December 26 up 49% to £8.9m. In the four weeks ending 26th December, Ocado’s sales were up 30% on a like-for-like basis reaching £40.8m.