Inflation in the U.K. rose to its highest rate in almost a year as the Iran war continues to ratchet up fuel prices, official figures showed Wednesday, cementing market expectations that the Bank of England will raise interest rates next month.

The Office for National Statistics said consumer prices rose by 3. 5% in the year to September, up from 3. 1% in August.

That's the highest reading since October last year, and above the 3. 4% that most economists had been expecting for the month.