Department store group John Lewis acknowledged that last week was “a challenging one” as the return of warmer weather discouraged shoppers, causing a total sales dip of 0.1 per cent, figures released today reveal.

Against tough comparatives last year, the chain had a difficult twelfth week of trading in its financial year, though fashion sales were boosted by the weather change.

In the week to April 20th 2013, sales of Fashion climbed 3.9 per cent as Womenswear, Accessories & Beauty and Childrenswear all traded strongly, with customers favouring Summer products including sunglasses and new season shoes.

Electricals and Home Technology sales suffered due to last year‘s iPad 3 launch and digital switchover, falling 0.7 per cent despite a rise in sales of small electricals and core imaging, up 22 per cent and 26 per cent respectively.

John Lewis Home sales also declined over the week, down 2.9 per cent on the same period last year though the retailer noted that Outdoor Living products are proving increasingly popular as Summer approaches.

Online sales however did see a rise, up 11 per cent on last year as Fashion categories enticed shoppers over the weekend, with trade rising 39 per cent.

Commenting on the significance of the chain‘s omnichannel strategy, John Lewis‘ online Director Michael Lewis said: “I would like to take the opportunity to thank the many Partners who have contributed to the recent relaunch of our online trading platform.

“The new platform will provide the foundations for future growth and allow us to further innovate our customer offer going forwards. For example, the new platform allows us to develop a much stronger mobile offer where our sales growth already regularly exceeds 150 per cent.

“Finally, it was with great pride this week that we were able to share externally that we are now trading at an annual run rate of over £1 billion online.

“This is an incredible achievement, not least because we have achieved it a year earlier than originally targeted.”

Sister grocer Waitrose also saw online sales soar, while sales of summery foods saw their strongest week so far this year, contributing to a total sales boost of 9.9 per cent.

Online sales surged 41.3 per cent compared with last year while average basket size in stores increased, as sales of prepared vegetables, exotic fruit and salads rose 28 per cent, 53 per cent and 12 per cent respectively.

Waitrose‘s latest TV advert helped aid sales of eggs, as free range egg sales increased 17 per cent while home baking ingredients, accessories and decorations saw a 39 per cent sales surge, while ready-made cake sales climbed 28 per cent.