Inflation fell to a four-year low of 2.1% in November as the rise in the price of food eased.
The Consumer Prices Index rate (CPI) has not been lower since November 2009, when it stood at 1.9%.
Today's figure from the Office for National Statistics (ONS) will ease pressure on the Bank of England as it brings inflation closer to its 2% target.
One reason behind the decline is that large rises in household energy bills have yet to take effect.
But the sting in the tail is that these are likely to make a large upward contribution in December's figures.