According to a survey by retail research firm GlobalData, the majority of customers at all major supermarkets—aside from Waitrose—support Labour.

Five years ago, the majority of shoppers chose Labour at Iceland, Co-op, and Asda.

Customers at Tesco, Sainsbury's, Morrisons, Lidl, and Aldi have reportedly shifted from Conservative to Labour since 2019. Ocado, the upscale online grocery store, had the largest percentage of Labour voters, followed by Iceland and Lidl, with Aldi in fourth place.

Between April 1 and May 12, GlobalData polled 3,177 nationally representative consumers to find out which supermarket chain they primarily shopped at for food and groceries and how they planned to vote in the upcoming general election.

Lead retail analyst Zoë Mills said: “If supermarkets were seats, Labour would be on course for a landslide victory, according to our supermarket election poll.

“When we asked the same questions during the 2019 general election campaign, the Conservatives held sway in all supermarkets except Asda, Iceland and the Co-op, having enticed Morrisons’ shoppers to vote blue and holding on to both Aldi and Lidl, which had previously been Labour in our pre-2017 election polls.”

At Waitrose the Tory lead has drastically reduced. In 2019, 48.2 per cent of the supermarket’s shoppers were Conservatives and 11.8 per cent Labour voters. This year 29.6% said they would vote Conservative and 28.4 per cent Labour.

Customers have also taken a liking to Reform UK. Of British supermarket customers, 11.9 per cent chose the party, knocking the Liberal Democrats down to fourth position.

Customers who shop at Co-op were the strongest supporters of the party led by Richard Tice. The survey found 23.2 per cent of them chose the new political party over the Conservatives, who had a 22.7 per cent share.

Mills proposed that the Co-op's extensive network of stores in south and south-east England, where Reform supporters are primarily concentrated, might account for the high percentage of its customers who support the party.

Aldi and M&S had the largest percentages of Green party supporters.