Retail research firm Kantar revealed that grocery price inflation leapt to 9.9% over the four weeks to July 10, rising sharply from 8.3% in the previous month.

Researchers said they saw the fastest increases in prices for products such as dog food, butter and milk.

Supply chain issues and labour pressures have added to costs in food production, which are now being fed back to shoppers.

Shoppers are set to see their grocery bills for the year leap by £454 after food and drink inflation hit the second-highest level on record.

Fraser McKevitt, head of retail and consumer insight at Kantar, said he expects the overall record for grocery inflation to be surpassed “come August”.

He added: “All this means that people will be feeling the pinch during our first restriction-free summer since 2019.

“Taking a barbecue as an example, buying burgers, halloumi and coleslaw for some al fresco dining would cost you 13%, 17% and 14% more than it would have this time last year.”

The researcher also said that supermarkets have seen a 14% jump in ice cream sales and a 66% rise for sun care products over the month as Britons experienced soaring temperatures.

It came as total supermarket sales increased by 0.1% over the 12 weeks to July 10, the first time the market has been in growth since April last year.

Lidl was the fastest growing supermarket again this period, with sales up by 13.9%. Aldi was also in double-digit growth, boosting its sales by 11.3% compared with last year.

Mr McKevitt commented : “Over 67% of people in Britain shopped in either an Aldi or a Lidl in the past 12 weeks, with 1.4 million additional households visiting at least one of the discounters in the latest three months compared with last year. Both retailers reached a new market share high over the past three months. Lidl now holds 7.0% of the market while Aldi climbed to a 9.1% share.”

Tesco returned to growth this period for the first time since October, the retailer boosted its sales by 0.1% and retained a market share of 27.1%. Ocado was the only other retailer in growth, holding its market share steady at 1.8% while its sales were up 0.7%.

Sainsbury’s holds 14.9% of the market, followed by Asda at 13.7%, and Morrisons 9.4%. Co-op achieved a 6.3% market share this period and Waitrose stands at 4.6%, according to Kantar. Frozen food specialist Iceland held its market share flat at 2.3%.

Mr McKevitt added: “There has been plenty of noise around the extreme heat sweeping across the country and we can definitely see people preparing to stay cool in the latest data.

“Over the past four weeks, sales of ice cream and suncare products soared by 14% and 66%. In July 2019, the last time we faced a heatwave like this, sales of fans, paddling pools and reusable water bottles grew by 107%, 169% and 17% respectively.

“ This added up to a combined total of £10.9 million extra spent during the hottest week on just those three categories, and we expect to see similar if not even bigger numbers this time around.”

Kantar monitors the take home grocery purchasing habits of 30,000 demographically representative households across the UK to provide an insight into the nation’s shopping habits.

Shoppers face £454 jump in annual grocery bills as food inflation soars