Upmarket grocery chain Waitrose saw its sales rise 6.3 per cent year-on-year last week thanks to Easter preparations, unseasonably warm weather and school holidays.

Its new Easter-themed advert featuring in-house celebrity chef Heston Blumenthal seems to have been well received, with sales of his Earl Grey & Mandarin Hot Cross Buns seeing soaring 6.3 per cent over the seven days ending March 31st 2012.

The hot weather inspired barbeques across the country with sales of associated meats up 270 per cent, while fish also had a strong week with mackerel up 28 per cent, smoked salmon sales growing 19 per cent and shellfish recording a spike of 78 per cent compared to the same period last year.

David Jones, Supply Chain Director at Waitrose, said: “Driven in part by the arrival of the Easter break, online shopping orders at Waitrose.com were up 35.1 per cent. The hot weather hasn‘t dampened inspiration in the kitchen ahead of Easter weekend or preparing the traditional Sunday roast.

“Sales of cookware increased by 45 per cent and sales of whole legs of lamb increased by a massive 210 per cent. The time of year has also brought out the party spirit, as sales of celebration cakes rose by 17 per cent.”

Trading was less spectacular at Waitrose ‘s sister retailer John Lewis, but the department store chain still improved on its performance for the same week last year with a 2.4 per cent rise in sales.

Concerns over fuel shortages and a different date for Mother Day dampened trading, but the warm weather boosted fashion sales and the impending digital switchover in many parts of the country continued to push television trading up.

Online sales and electricals & home technology sales were impressive, with increases of 37.2 per cent and 23.9 per cent respectively, but only four of its stores which have been open longer than 12 months managed to improved their trading figures year-on-year.