It is known as a premium retailer and is always the most expensive supermarket in The Grocer 33 weekly pricing survey. Yet this week, Waitrose claimed it was cheaper than hard discounter Aldi – in six of its 25 categories at least.

Unveiling a 2.5% rise in like-for-like sales for the six months to 26 July and a 5.5% increase in total sales to £2.03bn, MD Mark Price said Waitrose beat Aldi on entry-level pricing in white bread, rolls, beer, pickles, coffee and squash.

“We are more competitive and cheaper than Aldi,” he said. “If you look at beer, our entry-level price is £1.29. Aldi’s is £1.39. It’s just not true that the discounters are cheaper.”

The discounters relied on one-off deals and promotions on non-food items, he said, reiterating his claim that Waitrose was also 10% to 15% cheaper than M&S. The chain would put up more Price Commitment barkers to show how competitive it was, he said. It had already spent £30m on lowering prices and promotions in the past six months.

Waitrose was benefiting from the switch from eating out to in, said Price, citing a 33% increase in sales of its As Good As Going Out range. It was also keeping a lid on retail price rises. While it was paying 25% more for beef, it had only passed 10% of this on to customers. A 50% rise in lamb prices had not led to any price increase on shelf.

An 8.4% dip in operating profit was blamed on investment in new stores and technology, as well as property gains and pensions. Price confirmed Waitrose planned to launch a c-store format soon, but would not give further details.