The BRC said spending in its members' stores increased 3.9% in annual terms last month, well above the 1.1% fall a year ago.
May's retail sales growth was the slowest since the 1.6% recorded in October 2022 when consumers cut back on purchases as inflation soared to a 41-year high of 11.1%.
The BRC data is not adjusted for inflation, so May's sales growth reflects a fall in the volume of goods purchased.
Food was almost the only area where consumers spent more last month, due to higher prices as well as celebrations to mark the coronation of King Charles.
Separate figures from Barclays on Tuesday also showed high inflation and rising food prices continued to eat away at consumers' spending power.
Persons:
BRC, King Charles ., Paul Martin, Silvia Ardagna, Suban Abdulla, David Milliken
Organizations:
British Retail Consortium, Food, KPMG, Bank of England, Barclays, Thomson