Consumer spending has fallen annually for the first time in nearly four years, in signs that more households are reining back on purchases amidst rising prices and stalling wage growth.
Spending fell by 0.8% year-on-year in May, following a 0.3% increase in April, Visa's UK Consumer Spending Index found. It was the first annual fall since September 2013.
The fall was driven by a 5.3% annual decline in "bricks and mortar" spending on the high street, the quickest decline since April 2012.
By contrast, online spending was up by 6.9% year-on-year.
Kevin Jenkins, UK and Ireland managing director at Visa said: "Our index clearly shows that with rising prices and stalling wage growth, more of us are starting to feel the squeeze.
"Retailers of non-essential goods were among the worst hit, with clothing and household goods seeing sharp declines in sales.
"The experience sectors continued to record some growth, though at much softer rates, suggesting consumers were reining in their discretionary spending.
"Bricks and mortar retailers had a particularly challenging month, with sales dropping at the quickest level in over five years, at a time when warmer weather and the May bank holidays would usually drive shoppers on to the high street.
"Online retailers, on the other hand, fared well, with spend up 6.9%."
Looking at different spending categories, the strongest spending shrink in May was in the transport and communication sector, where spending fell by 7.9% annually.
This was followed by clothing and footwear, which recorded the fastest fall in spending for this category since April 2012. Spending on clothing and footwear declined by 5.2% annually in May.
Spending on household goods was down by 4.1%, the quickest fall in spending in this category since March 2013.
Food and drink spending also saw a marginal year-on-year decline, with a 0.6% fall.
Among the sectors which saw an increase in spending year-on-year, miscellaneous goods and services - a category which includes trips to the hairdressers and jewellery - saw the fastest annual increase in expenditure, with a 7.1% annual uplift in May.
Spending in hotels, restaurants and bars was up by 3.3% annually, while expenditure on recreation and culture saw 2.2% annual growth.
The index uses spending on Visa cards as a base and adjusts the figures to reflect overall expenditure, not just that on cards.
Annabel Fiddes, an economist at IHS Markit, which compiles the index, said: "The outlook for consumer spending continues to look relatively bleak, with households facing faster increases in living costs and muted wage growth.
"The squeeze on household finances is likely to get worse as the Bank of England forecasts faster increases in consumer prices in the coming months.
"Combined with relatively low levels of consumer confidence, uncertainty around the outcome of Brexit and a slowdown in UK economic growth, it's likely we will continue to see weaker expenditure trends at least in the near-term."