The cost of British food staples including cheddar cheese, porridge oats and white bread has soared in the last year, according to a new Which? report.

Overall inflation on food and drinks across eight major supermarkets – Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose – rose to 17.2% in March.

This marks a rise from 16.5% the previous month.

But staple foods in British diets have seen much bigger price increases.

The price of porridge oats increased by 35.5% across all supermarkets compared to a year ago while cheddar cheese prices increased by 28.3%.

Meanwhile, pork sausages saw an average price increase of 26.8% while the average inflation of the price of white potatoes was 14%.

White bread also rose by an average of 22.8%.

Read more: Grocery inflation hits new record high – and the worst is yet to come

But individual supermarkets introduced price hikes of up to 80% on these staple items.

Asda’s Dragon Welsh Mature Cheddar 180g increased from £1 in the three months to the end of March last year to £1.80 across the same period this year – an 80% increase.

Meanwhile, The Bakery at Asda Soft White Medium Sliced Bread 800g increased by 67% from 56p to 94p.

Also at Asda, its Just Essentials budget range of eight sausages increased in price by 73.5% from 81p to £1.40.

Quaker Oat So Simple Protein Porridge Pot Original 49g at Ocado went from 94p to £1.56 – an increase of 65.5%.

Tesco’s value Woodside Farms pack of eight sausages went from 80p to £1.39, a 73.3% increase.

At Morrisons, a four-pack of baking potatoes increased from 40p to 66p – a rise of 63.5%.

While supermarkets’ own-label budget items are still the cheapest products, they saw the highest rate of inflation among all products – up 24.8% in March compared with the same time last year.

Standard supermarket own brands saw price rises of 20.5% while prices of premium own-brand ranges increased by 13.8%.

Which? analysed inflation on more than 26,000 food and drink products at the eight supermarkets.

It also selected a basket of staple foods including cheddar cheese, sliced white bread, pork sausages, white potatoes and porridge oats to find which products had seen the biggest price hikes.

Which? is encouraging supermarkets to make their budget lines more widely available and pricing more transparent.

Sue Davies, Which? head of food policy, said: “Our latest supermarket food and drink tracker paints a bleak picture for the millions of households already skipping meals of how inflation is impacting prices on supermarket shelves, with the poorest once again feeling the brunt of the cost-of-living crisis.

“While the whole food chain affects prices, supermarkets have the power to do more to support people who are struggling, including ensuring everyone has easy access to basic, affordable food ranges at a store near them, particularly in areas where people are most in need.

“Supermarkets must also provide transparent pricing so people can easily work out which products offer the best value.”

A Tesco spokesperson said it remains “absolutely focused on providing great value for our customers. Our market-leading combination of Aldi Price Match, Low Everyday Prices, and Clubcard Prices means we are the most competitive we have ever been”.

“So whether it’s price matching Aldi on the basics, locking the price of more than a thousand household staples until July 2023, or offering exclusive deals and rewards through thousands of Clubcard Prices – we’re more committed than ever to providing our customers with great value,” they added.