The headline rate of inflation rose to 3.3% in September, the National Statistics office reported.

The September inflation figures are used to upgrade pensions, and should mean a weekly increase in pensions of �2.23 from next April.

This is three times this year's increase of 75p, the size of which provoked widespread discontent.

The underlying rate of inflation - which excludes volatile mortgage costs and is closely watched by the Bank of England - rose a higher-than-expected 2.2% on the year.

Pensions rising

Chancellor Gordon Brown has signalled that next year's pension rise would be above inflation.

He is expected to give details of the increase when he delivers his annual pre-Budget report in the next few weeks.

A single person's state pension is now just under �70 a week and the �2.23 weekly rise is thought unlikely to satisfy union demands to bring pensions in line with average earnings.

While the rise in headline inflation may be good news for pensioners, the rise in the underlying rate of inflation increases worries that the Bank of England's Monetary Policy Committee may raise interest rates again.

The underlying rate of inflation is still comfortably below the 2.5% target the government has set for the MPC.

Inflation has been below the government target for the past 18 months.

Oil prices

Prices were boosted by rising petrol prices, the National Statistics office said.

The prices of household goods also rose as the summer sales ended.

However, the office expects that these price rises will be reversed in October, once the mid season sales start.

Bank of America analyst Jeremy Hawkins said:" [It] is still below the 2.5% target but it will still worry the MPC hawks especially with the labour market so tight, the autumn wage round due to start and the headline rate now up to 3.3%.

"We still think that the odds are against a hike next month but the risks are building."