Inflation is now at a four decade high but the increase in May was far lower than the previous month when inflation rose by 2 percentage points from 7% to 9%.

The Bank of England Monetary Police Committee has forecast that CPI could reach 11% by October.

ONS said food price inflation and petrol price increases were particular factors in the increase.

ONS chief economist Grant Fitzner said: "Though still at historically high levels, the annual inflation rate was little changed in May. Continued steep food price rises and record high petrol prices were offset by clothing costs rising by less than this time last year and a drop in often fluctuating computer games prices.  

“The price of goods leaving factories rose at their fastest rate in 45 years, driven by widespread food price rises, while the cost of raw materials leapt at their fastest rate on record.” 

Daniel Casali, chief investment strategist at Evelyn Partners, said: "Despite the modest deceleration in core CPI inflation and recent weakening economic activity in the latest monthly GDP stats, money markets have priced-in that the Bank of England’s Monetary Policy Committee (MPC) will still raise interest rates by 0.5% points at the next three meetings (4 August, 15 September and 3 November). If realised, the BOE current base rate of 1.25% would rise to 2.75% by November and to around 3.6% over the next 12 months."

Laura Suter, head of personal finance at AJ Bell, said: “A slight uptick in inflation in May to 9.1% means that the UK public have been spared double digit inflation for now, but it’s just around the corner. RPI inflation, which is what many of us see our bills increase by every year, has now hit 11.7% - another 40-year high.

“Once again fuel is the factor driving inflation higher, from home energy bills to petrol and diesel prices pushing up transport costs. As a result of rising energy costs, the 12-month inflation rate for electricity is 53.5% and for gas is an eye-watering 95.5%. And May saw another record broken, with the largest increase in transport costs since records began in 2006. As a result of petrol and diesel prices hitting new records in May, the 12-month inflation rate for motor fuels hit the highest rate since 1989 – when the figures were first calculated."

In May the CPI monthly increase was 0.7% compared to 2.5% in April. 

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