UK households' real spending power fell 0.6% in the first three months of the year as wages failed to keep up with rising prices, squeezing families' finances to the lowest level since 2005, according to data from the Office for National Statistics.
An alternative figure for households' disposable income, including benefits and accounting for tax, showed an even steeper fall of 1% in the first quarter. A spokesman for the ONS said that was largely down to cuts in benefits and higher taxes.
Brendan Barber, general secretary of the TUC, said: "Households across the UK are suffering the tightest squeeze in living standards since the 1920s, causing hardship for families and dragging down the economy. But rather than easing the burden, the government has made things worse by hiking VAT and cutting much needed tax credits."
Shrinking bank balances led to Britons reining in spending, and real expenditure per head dropped to its second lowest level in almost a decade, down 0.2% in the first three months of the year.