Christmas came early for some bakery businesses, with supermarkets already selling more than £5m worth of Christmas puds and mince pies in recent weeks.

Brits splashed out £4m on mince pies and £1.1m on Christmas puddings in the four weeks ending 8 October, according to data from retail analyst Kantar Worldpanel.

The grocery market share data also showed supermarket sales were up 3.1% year-on-year in the 12 weeks to 8 October, the 17th consecutive period of growth for Britain’s grocers.

While sales have grown at each of the big four supermarkets – Tesco, Asda, Morrisons and Sainsbury’s – they have lost market share as smaller operators continue to woo new customers (see table below).

“Aldi and Lidl collectively added an additional £390m in sales this quarter, which accounts for half of the entire market’s overall growth this period,” said Kantar Worldpanel retail and consumer insight head Fraser McKevitt.

Lidl was Britain’s fastest-growing supermarket, with sales up 16%, while Aldi grew 13.4%. Share increased for both retailers by 0.6 percentage points, up 5.2% for Lidl and 6.8% for Aldi.

Strong sales of products, including cakes and pastries, helped Morrisons become the fastest-growing of the big four retailers over the period, increasing sales by 2.8%. Despite the growth, its overall market share fell 0.1 percentage points to 10.3%.

Tesco sales grew 2.1% in the past 12 weeks, with Sainsbury’s up 1.9% and Asda up 1.8%.

“Despite traditionally selling a higher proportion of brands than its major rivals, it is own-label sales that are driving the growth at Asda,” added McKevitt. “They now account for 45% of sales, with Asda’s value-focused Farm Stores line and premium Extra Special range leading the charge.”

Overall, online sales growth has slowed to 6.7% from a recent high of 21.9% in October 2014.