The chairman of Asda has warned Rachel Reeves against a fresh tax raid in the upcoming Budget as food inflation hammers shoppers.

Allan Leighton said that if the Chancellor wanted to grow the economy she should move away from “taxing everything in some way, shape or form” and instead start investing in Britain.

It comes amid speculation that Ms Reeves will have to find as much as £50bn in the autumn to repair a hole in public finances.

The Chancellor is understood to be considering extending a freeze on income tax thresholds, mounting a raid on the gambling sector and introducing a “mansion tax” on the sale of expensive properties.

Ms Reeves is also reportedly looking at applying National Insurance to rental payments.

Separately, the Chancellor is preparing to increase business rates for bigger premises, reforms that are expected to lead to higher bills for larger supermarkets.

Mr Leighton called the changes “very unhelpful”, echoing concerns from rival grocery giants Tesco and Sainsbury’s over Ms Reeves’s planned £1.7bn business rates raid.

The Asda executive chairman said: “All these things don’t make life easier. They are contributing to inflation, and inflation is hitting the pocket of the consumer.”

Figures from Asda this week revealed that middle-class families’ disposable incomes had fallen for the first time in two years. The British Retail Consortium also said food inflation accelerated to 4.2pc.

Meanwhile, poor households’ living costs are surging at the fastest pace since the start of last year as rising rents, bills and food prices hammer budgets. Those with low incomes suffered a 4.1pc rise in the cost of living in the 12 months to June, according to the Office for National Statistics, the fastest rise of any income grouping.

Peter Matejic, of the Joseph Rowntree Foundation, said: “Rising prices are particularly troubling for low-income families. When the cost of these essentials starts rising quickly, they are left with no choice but to fall behind on bills, use loans to try and get by or go without essentials, like the seven million low-income families who did so in summer this year.”

Mr Leighton said supermarkets were battling to “find a way through” and keep down prices for customers.

Asda has been stepping up pressure on its suppliers to cut their own prices in recent months, as part of a plan to help win back shoppers.

Earlier this month, The Telegraph revealed Asda had told food giants including Heinz, Nestlé and General Mills that they needed to “share the load” in offering price cuts.

Mr Leighton suggested many suppliers were willing to take some of the pain, saying: “We try to do the right thing for the customer and if the suppliers want to come with us, and a lot of them do, then we take that support.

“But if we think it’s the right thing to do for the customer, we’re going to do it anyway.”

New figures published on Thursday showed early signs that Asda’s turnaround effort is starting to yield results.

Sales were down 0.2pc on a like-for-like basis in the three months to the end of June, but this marked its best quarterly sales performance since early last year. Asda recorded revenues of £5.3bn for the period.

However, the supermarket warned that sales would take a hit in the latest period amid disruption from the race to complete its long-awaited IT upgrade.

Asda has spent four years working on the botched upgrade, dubbed Project Future, which has been mired with a series of setbacks.

The supermarket has now completed a £1bn programme to disentangle its computer systems from former owner Walmart this week, six months later than planned.

Mr Leighton said Asda needed to put the programme “behind us” to allow it to push ahead with turnaround plans.

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