Waitrose sales edged up 0.8% in the week ending December 7.

The upmarket grocer, which the previous week reported a 6.5% rise in sales, said its performance was distorted by the earlier finish of its ‘Four Festive Shops’ promotion. Waitrose retail director Rob Collins said that in the equivalent period last year the promotion was still “driving additional sales in our shops”.

Collins said shoppers are being savvy in their buying choices, “balancing extravagant purchases with saving money in other areas”. More than 31.4% of sales were on promotion, up 1.7% compared to last year. Offers on luxury items did “particularly well”. For example sales of frozen lobster, at present a third off, were up 10% and “proving a dinner party must-have”, according to Collins.

The grocer reported that its shoppers have been sprucing up their homes in preparation for Christmas guests. Sales of window cleaning products rose 10%, metal polishes for cutlery were up 18%, and quilted cashmere toilet roll was ahead 109%.

Sales of Christmas plants bloomed, with poinsettias and wreaths both up 50%. The Heston from Waitrose Box of Chocolates has become one of the top selling box of chocolates at the grocer as shoppers search for one of five tickets hidden inside that win them a day with the celebrity chef.