Butter, milk, and spaghetti are among the goods that have got much dearer, new figures revealed on Wednesday. Households are already grappling with huge increases in the price of energy and fuels like petrol and diesel. But analysis shows that a four-pint carton of milk now costs, on average, 34p more than it did 12 months ago.

The cost of an average 500g pack of own-brand spaghetti has also rocketed up by 33p, from 52p to 85p, since August last year while a 500g of Lurpak is now 63p more expensive, up from £3.58 last year to £4.21 this year.

While the rise in costs of wheat and dairy items has been well documented, baked beans are included in the list of high-inflation items.

An average six-pack of Heinz baked beans now costs as much as £5 in some stores, sparking fury from shoppers.

The analysis shows how an average 20-item shopping basket now costs £5.20 more than it did last year with shoppers in Tesco and Morrisons seeing some of the biggest rises.

It comes as the British Retail Consortium, the trade association for supermarkets and retail businesses, released its own figures showing how prices have risen.

The BRC, quoting figures from data firm NielsenIQ, said it had seen the costs of staple items rocket by 9.3 percent year-on-year up from seven percent last month.

Cash-strapped Britons are already bracing for sky-high energy bills this winter when the price cap on energy costs for an average home are set to rise to £3,500-a-year, a rise of more than 80 percent.

Helen Dickinson OBE, Chief Executive of the British Retail Consortium, said: “Mounting cost pressures up and down supply chains meant shop price inflation hit a new high in August.

“The war in Ukraine, and consequent rise in the price of animal feed, fertiliser, wheat and vegetable oils continued to push up food prices.

“Fresh food inflation, in particular, surged to its highest level since 2008 and products such as milk, margarine and crisps saw the biggest rises.

“The rise in shop prices is playing into wider UK inflation, which some analysts are predicting could top 18 percent in 2023. The situation is bleak for both consumers and retailers, but retail businesses will remain committed to supporting their customers through offering discounts to vulnerable groups, expanding value ranges, fixing prices of essentials, and raising staff pay.

“However, as retailers also grapple with growing cost pressures, there is only so much they can shoulder.

“The new Prime Minister will have an opportunity to relieve some of the cost burden bearing down on retailers, like the upcoming increase in business rates, in order to help retailers do more to help their customers.”