Economists today forecast further rises in inflation after the Consumer Prices Index (CPI) reached its highest level in more than a year.

Sky-high fuel prices were the main driver behind the rise in the CPI to 1.5% in May from 1.2% during the previous month, according to the Office for National Statistics (ONS).

With the cost of crude oil surging to a record high of more than 42 US dollars a barrel in New York, fuel costs added 0.2% to the rate of inflation in May alone.

The cost of a litre of unleaded petrol rose to 81.8p in May from 78p in the previous month, compared with significant cuts in petrol prices a year ago.

HSBC economist John Butler said inflation would ''jump up again in June, again because of higher oil prices''.

Inflation was likely to run between 1.75% and 2.25% over the next two years, but this did not pose an immediate threat to the UK economy because underlying pressures were benign, he said.

Gerrard chief economist Simon Rubinsohn said signs of a new petrol price war led by the supermarkets might help to restrain inflation this summer.

But he added: ''The risk is that CPI inflation will edge higher over the coming months.''

Inflation on the CPI basis was last higher in March last year when the annual rate was 1.6%, the ONS said.

Transport costs were also boosted by seasonal price increases in airfares, which fell a year ago due to the timing of Easter.

Food provided the greatest downward pressure, with prices rising by less than a year ago, helped by reductions in the cost of fish, poultry and cakes.

Promotional deals on furniture and home furnishings such as carpets also limited the rise in inflation, the ONS said.