Shoppers are forecast to spend £6.8 billion at supermarkets in the fortnight before Christmas Eve, up £100 million since last year.
According to NielsenIQ data, shopping basket values increased 2.6% in the four weeks to 4 December, as people “treat themselves to more premium and higher value items”.
Although online grocery sales are down 13%, this is against the high watermark of last year’s lockdown.
Marks & Spencer has the fastest-growing 12 week sales on 9.1%, followed by the discounters Lidl (8.3%) and Aldi (4.6%).
Every other supermarket saw a drop here, with Tesco down 0.7%, Asda 4.2%, Sainsbury’s 4.6% and Morrisons 5.6%.
NielsenIQ head of retailer Mike Watkins said the Big 4’s performance was “weaker”, but noted this was “against strong comparatives last year when the nation was in lockdown”.
He continued: “The sales figures in November are partly due to lockdown comparatives but also shoppers delaying big shopping trips until the final week before Christmas.
“We anticipate that the 23rd December is likely to be the peak day for trading at UK supermarkets.”