John Lewis’ sales advanced 13.3% to £64.3m last week, as it generated double-digit sales increases across 16 stores and online.

The department store retailer said the week to March 2 was “extremely strong”, confirming the underlying performance of the retailer with half term now out of the way.

Last week 16 stores traded in double figures, with its two new format shops in Swindon and Tamworth top performers. Its like-for-like trading shops generated particularly good results.

Online sales also delivered a double-digit increase as the new website bedded in, delivering sales up 21.7% last week.

Electricals drove the sales performance due to the availability on key technology lines and an extended guarantee promotion. John Lewis called its Oxford Street flagship a “powerhouse” in UK electricals retailing, with sales up 10.9% last week.

John Lewis reported an increase in price-matching through its Never Knowingly Undersold strategy. This boosted beauty and fashion last week as competitors have started early price cutting.

Yesterday the John Lewis Partnership, which comprises John Lewis and Waitrose, revealed staff will receive bonuses worth 17% of their salary after the group reported a 15.8% surge in pre-tax profits for the year to January 26.

Director of retail services Barry Matheson said: “This year has started out in an even stronger vein but there can be no room for complacency as there are some stiffer numbers ahead of us in the weeks to come, particularly around Easter. But that is a challenge I am sure we will all face with relish.”

Waitrose generated a 10.6% increase in sales, excluding petrol, totalling £113.9m.

Cold weather helped drive sales of roasting meats. The grocer reported a 29% rise in beef joint sales, a 42% surge in gammon joints and a 21% increase in lamb. Shoppers also bought 18% more frozen Yorkshire puddings.

Customers have also been warming up with soup, hot drinks and oven chips, which were up 38%, 32% and 31% respectively.

Waitrose said customers had started buying presents for Mother’s Day, as sales of luxury brand toiletries, such as Cath Kidston and Neal’s Yard Remedies, rocketed 91% last week. Boxes of chocolates were up 45%.

Customers are already stocking up for Easter. Sales of Waitrose’s Heston Blumenthal Earl Grey and mandarin hot cross buns rocketed 175% last week.