UK inflation recorded its sharpest jump in more than two years in September, even without any direct evidence of the weaker pound pushing up prices.
Annual UK consumer price inflation rose to 1% from 0.6% in August, the highest level since November 2014 and the biggest jump from one month to the next since June 2014, the Office for National Statistics said.
Economists polled by Reuters had expected a reading of 0.9%, and today's figure was at the top end of the range of forecasts.
They are likely to view September's rise as only the start of a much broader increase, fuelled by the pound's near 20% plunge since June's vote to leave the European Union.
The stronger than expected figures which will further dampen expectations that the Bank of England will cut interest rates again this year.
Bank of England Governor Mark Carney last week said the central bank could tolerate "a bit" of an overshoot against its inflation target, to help accommodate economic growth and employment.
Official statisticians said they were waiting for clear signs of an impact from the weakened currency.
Most of the rise in inflation in September was due to the biggest monthly jump in clothing prices since 2010 and a rise in fuel costs, which had been falling a year earlier.
Looking at the three months to September as a whole, prices were up 0.7% on a year earlier compared to the Bank of England's forecast for inflation to average 0.76% over the period.
The Bank of England had forecast in August that inflation would pick up sharply to hit its 2% target in around a year and then overshoot for the next couple of years, as sterling's big fall after Britain's vote to leave the EU pushes up the cost of imports.
But the surge in inflation risks proving bigger, after sterling plunged to its lowest level on record against a basket of currencies last week, something which is likely to force the bank to revise up its inflation forecasts next month.
The slide in sterling - combined with evidence that the economy is slowing by somewhat less than the Bank of England thought likely also means few economists now expect the it to press on with plans to cut interest rates to a new record low next month.
A pricing row last week between Britain's biggest retailer, Tesco, and one of the world's largest consumer goods companies, Unilever, was a first clear sign for consumers of the turbulence unleashed by the Brexit vote and of higher inflation to come.
The pound's fall - down 19% against the US currency and over 16% against the euro - has left suppliers and retailers battling for profits as imported goods become more expensive.
Tesco briefly halted online sales of goods produced by Unilever - which owns brands such as Marmite and Ben & Jerry's ice cream - because of the increase in prices.
UK inflation has been below the Bank of England's 2% target for nearly three years and last year it was zero, the lowest since comparable records began in 1950.
An ONS measure of core consumer price inflation - which strips out changes in the price of energy, food, alcohol and tobacco - rose to 1.5% from 1.3%, slightly above economists' expectations for 1.4%.
Factory gate prices increased 1.2%, the biggest increase in three years, and slightly stronger than forecasts of a 1.1% annual increase.
The ONS also released figures for August house prices, which showed an 8.4% annual rise across the UK as a whole compared with 8% in July.
Prices in London alone increased by 12.1% in August.