The rate of price rises has remained 8.7% despite expectations of a fall, according to official figures.
The Office for National Statistics (ONS) announced the consumer price index measure of inflation stood at 8.7% in the year up to May, the same as the rate in April.
A slight decrease, to 8.4%, had been expected by economists.
The Bank of England has undertaken a programme of interest rate rises to bring inflation down to 2% and Wednesday’s figure will be closely watched by rate-setters ahead of the latest expected rise on Thursday.
Inflation began to increase in late 2021, when supply chain problems linked to COVID lockdowns and the associated worker shortages meant demand for goods could not be met.
Russia’s invasion of Ukraine exacerbated the problem as many countries, particularly those in Europe, scrambled to find other energy sources and reduce their use of Russian gas, which subsequently pushed up the cost of energy and many other goods.