Shop price inflation rose to 2.1% in December, up from 2% in November, as rising costs pushed prices up.

Food inflation remained unchanged at 4% last month, as “unprecedented levels of discounting” took the “sting out of grocery shopping”, according to Stephen Robertson, director general at the British Retail Consortium, which compiled the figures, along with Nielsen.

Non-food inflation increased to 1.1% in December, compared with 0.9% in November.

Robertson said: “Retailers are protecting British consumers from the full-force of global commodity cost increases.

“A string of costs are higher than a year ago. Extreme weather and poor harvests have driven coffee up 52 per cent, wheat 45 per cent and soya beans 38 per cent yet the shop price of food is up only 4%.

“Overall shop price inflation is well below the wider Consumer Price Index, though price increases in some non-food goods pushed that figure up slightly compared with November. That’s consistent with warnings from some retailers that inflationary pressures are working through to prices.

“Next month’s figures will show the initial impact of the latest VAT increase. Retailers know that customers are worried about their jobs and personal finances. The competitive retail environment will mean stores go on doing all they can to limit price rises.”