The quantity of goods and services bought by households dropped 2.3% in April, according to the Office for National Statistics (ONS).
Only a 0.4% fall was predicted by economists polled by news agency Reuters.
Retail sales figures are significant as household consumption, measured by the data, is the largest expenditure across the UK economy.
It can play into overall economic growth, measured through gross domestic product (GDP) – a metric that Prime Minister Rishi Sunak will be watching.
