John Lewis sales surged 12.9% to £65.59m in the week to September 15.

Electricals and home technology sales grew 19.3% as promotional activity such as trade-ins and additional guarantees “boosted growth”, according to John Lewis operations director Dino Rocos.

He added that the new entry-level Kindle, which launches this week, “will add to the good sales we are seeing in the tablets assortment”.

Fashion sales were up 16% with womenswear and women’s accessories and beauty delivering “notable increases” of 21.3% and 21.8% on last year respectively. The growth was aided by a price matching promotion.

The home category delivered a sales uplift of 6.1%, as “continued strength in availability across core sites” propelled growth.

Online sales accounted for a quarter of trade, with click-an-collect sales more than doubling on last year. The Exeter pop-up shop is also “pulling in trade” via click-and-collect.

Web sales rocketed 38% with a “strong conversion of click into demand and the cooler weather showing sales in seasonal areas”.  

Rocos added: “With the Never Knowingly Undersold advert ‘What’s Important Doesn’t Change’ launching over the weekend, the John Lewis brand is trending on social media and should mean an exciting week ahead.”

At sister retailer Waitrose, sales rose 7.7% to £106.6m last week, with sales of summer food dominating as Brits aimed to make the most of the last glimpses of sunshine.

Sales of burgers and sausages were up, as well as icecream, Pimms and sun lotion.

The upmarket grocer also began to see the beginning of autumn trends, with sales of apples and plums helping to push the overall fruit category up by 14%.