Between March and May, pay excluding bonuses was down 2.8% from a year earlier when adjusted for inflation - the fastest drop since records began. Pay including bonuses was down 0.9% when adjusted for inflation.
For March to May, average total pay for the private sector was 7.2% higher than the same period last year, before taking account of inflation, according to the Office for National Statistics (ONS). For the public sector the figure was 1.5%.
With inflation at a 40-year high and household budgets are being hit by soaring food, fuel and energy costs unions are calling for wages to reflect the cost of living.
TUC general secretary, Frances O’Grady, said candidates in the Conservative party leadership election should be mindful that “UK workers are suffering the worst pay squeeze in modern history”. She added: “The priority for the country must be to get wages rising across the economy – not tax cuts.”