The trade association’s Tom Holder said the disparity suggested supermarkets were increasing the costs of premium-brand products faster than their “essentials” and “basics” ranges.

“Supermarkets want to be known for offering a stable price on certain items for their shoppers, whether that is being the cheapest for avocados, or having the best basic range – so they will offset the cost of freezing prices in some areas by upping prices elsewhere,” he said. 

He pointed to Asda’s pledge earlier this month to maintain its cheapest “smart price” and “farm stores” food ranges for lower-income shoppers in the face of pressure from food poverty campaigners. The ranges include 1kg bags of rice for 45p and tins of chopped tomatoes for 28p.

Trolley.co.uk found the biggest increase in price was for hand sanitiser. Cuticura antibacterial hand gel was 300pc more expensive over the year, while Dettol’s version rose by 208pc. Some of the smallest rises were for cheap cigarettes and tobacco rolling paper.

A box of Scott’s Old Fashioned Porridge Oats, Twinings green tea bags and The Collective yoghurts are all now a third more expensive than at this time last year.

Imported goods have also increased significantly in price. A bottle of Filippo Berio olive oil will cost you £4.50 today, up 50pc from its £3 price tag in February last year, while Mutti chopped tomatoes are now £1.20 a can, up from 90p – a 33pc rise.

“The cost of shipping goods from overseas in particular has become very costly due to the increased cost of oil,” Mr Holder added.

Organic goods are up too. A tin of Heinz organic baked beans comes in at £1, up 25pc from 80p last year, while the non-organic version is up 18pc. Knorr’s organic chicken stock pots are 11pc more expensive than last year, now costing £2.

A typical shop at Britain’s “poshest” supermarket, Waitrose, rose by 9.2pc last year, a report from consumer group Which? found last month. The cheapest supermarkets, Lidl and Aldi, increased their prices by 5.1pc and 4.3pc over the same period, while Sainsbury’s raised them by just 0.59pc.

Shortages in the supply of carbon dioxide, used to stun animals and store food, as well as higher prices for fuel needed to transport products, have also added to costs. There are also labour shortages due to large numbers of foreign workers leaving the country because of coronavirus, highlighted by the HGV driver crisis.

Poor harvests have also resulted in increased prices on the shelves. Wheat prices have gone up due to droughts in Russia, North America and Argentina, according to The Food Foundation, a charity.