UK inflation has fallen below the Bank of England's target of 2 per cent for the first time in more than four years.
Inflation as measured by the Consumer Prices Index (CPI) dropped to 1.9 per cent in January from 2 per cent in December, the Office for National Statistics said.
The biggest factor in driving down inflation was a fall in recreation and culture prices, household goods, alcoholic beverages and tobacco.
Prime Minister David Cameron said in a message on Twitter: "Today's fall in inflation is more evidence our long-term economic plan is working. We want to ensure a secure future for hard-working people."
The fall in inflation is likely to bolster the Bank's pledge to keep interest rates on hold at a record low of 0.5 per cent and give governor Mark Carney breathing space before the first hike takes place.
Last week the Bank upgraded its growth forecast for the UK economy to 3.4 per cent from 2.8 per cent and hinted interest rates are unlikely to rise until 2015.
Chris Williamson, chief economist at Markit, said: "The UK economy is enjoying a welcome combination of strong economic growth and low inflation.
"This 'Goldilocks' scenario adds to the scope for policymakers to keep their foot on the accelerator for longer via lower interest rates to help drive a strong and more sustainable recovery."
Inflation as measured by the Retail Price Index (RPI) , which includes housing costs, rose to 2.8 per cent from 2.7 per cent in December.