Aldi’s rapid market growth continues unabated after announcing a 13.5% rise in sales in 2016 and committing to 70 new store openings next year.

Sales in the UK and Ireland reached £8.7bn in the year to 31 December 2016, with like-for-like sales “strongly positive” over the 12-month period.

However, operating profit declined by 17% to £211.3m as a result of the discounter’s “continued investment in prices” and infrastructure.

Aldi currently operates 726 UK stores and is aiming for 1,000 stores by 2022, with 23 openings planned in the final three months of the year.

The company’s best-performing categories were its Specially Selected range of premium quality products, alongside fresh fruit and veg, fish and meat. In the current year so far, sales of Specially Selected are up 40%.

Aldi is investing £300m in its Project Fresh initiative to create more in-store space for fresh, chilled and food-to-go ranges. The initiative will also involve simpler layouts, improved fixtures and brighter, wider aisles. By the end of 2018, a total of 250 stores will have launched in the new format.

Aldi CEO UK and Ireland, Matthew Barnes, said: “Our growth is accelerating, thanks to the hundreds of thousands of new customers switching their shop to Aldi. This is happening right across the UK and is all down to a simple, straightforward commitment – products comparable to the leading brands and supermarket premium ranges at the lowest prices in Britain.

“We’re doing everything we can to insulate customers from those cost increases, making sure our prices are the lowest in the UK, every day of the year.

“At the same time, we’ve been improving the quality of our range and introducing the new products our customers have asked for. The result is a carefully selected range of exclusive own-label brands and award-winning products.”