Inflation reached 4.4 percent in July – the highest since the early 1990s and more than double the government’s target – as economists predict a further rise to 5 percent in the autumn. Rises in food prices, fuel costs and disappointing price cuts in the summer sales, have caused this latest jump, which marks the fourth monthly increase in the consumer price index.

In the Bank of England’s last quarterly forecast in May, it gave less than 10 percent probability that inflation would be as high as it is now. The bank will set out its latest forecasts for the economy and inflation on Wednesday.

Several economists expect that the Bank might even be forced to raise rates to bolster its diminishing reputation for keeping to close to target. Very few economists expect rate cuts this year.

The Bank’s forecasts on Wednesday will show that, apart from two brief interludes, it expects inflation to be too high for the five-year stretch between the summers of 2005 and 2010. High inflation in July was also feed further rises next January when regulated train fairs raise by at least 6 percent, 1 percent more than the 5 percent rise in the retail prices index last month.

Economists say the figures were shocking because they were worse than those in other countries, and were not limited to food and petrol price rises and did not yet include announced rises in gas and electricity prices. Relief will come, however, from falling oil and grain prices in the coming months, but this will take quite some time to work into lower consumer price inflation.

Vincent Cable, the Liberal Democrat Treasury spokesman, said: “It’s very clear that we’re in for a dose of stagflation, with the economy slowing abruptly and inflation too high and increasing.”