The figures, covering the four weeks to 4 October, show spending on promotions was up by more than £250m compared with the same period last year. Worldpanel said special offers remained an important tool for shoppers hoping to manage their grocery bills, or to make pricier items and larger packs more affordable.
Fraser McKevitt, head of retail and consumer insight at Worldpanel, said the cost of living continued to weigh heavily on shoppers with the autumn budget approaching, and that the cost of filling up a car was adding to pressure on household budgets. More than half of shoppers reported being very or extremely worried about petrol prices, and almost one in three said it was already taking a real toll on their finances.
"Until the chancellor sets out his plans, we expect that caution to carry on showing up at the till," McKevitt said.
There was some good news for households preparing for Halloween: like-for-like chocolate confectionery prices are 3% lower than a year ago, which McKevitt said would help ease pressure on budgets as the festive season approaches, even though it would not fully reverse the double-digit increases of 2025. About 1.2 million households bought a pumpkin over the latest four weeks, up 10% on last year, while more than 250,000 households purchased a pumpkin spice coffee.
Among individual retailers, Lidl led in market share gains over the 12 weeks to 4 October, climbing to 8.6% on the back of a 7.1% increase in sales driven by fruit, vegetables and wine. Ocado's sales increased by 12.4%, outpacing overall online sales growth of 5.5%. Tesco held a 27.8% share with till spending up 1%, while Sainsbury's held 15.2% with spending up 1.3%. Asda's share now stands at 11.5%, and Aldi holds 10.5%, with sales at the discounter up 0.4% year on year. Grocery sales at Marks & Spencer rose by 14.9%.