One of the measures of UK inflation is expected to fall below zero - a sign of falling prices - when figures are released later.
A key measure of UK inflation has fallen to zero for the first time in 49 years, official figures show.
Economists expect the Retail Prices Index (RPI), which includes housing costs, to have declined for the first time in 49 years.
The Retail Prices Index (RPI), which includes housing costs, fell to 0% in February from 0.1% in January - the lowest reading since March 1960.
If so, it will raise fears the UK is facing a damaging bout of deflation.
There are concerns that if prices keep falling, this could lead to a prolonged period of deflation.
The Consumer Prices Index (CPI), which is used in economic policy, is expected to show prices have risen by 2.6%.
Meanwhile the Consumer Prices Index (CPI), which is used in economic policy, rose unexpectedly to 3.2%.
The Office for National Statistics (ONS) is due to announce both measures at 0930 GMT on Tuesday.
The fall in RPI, as seen by the latest Office for National Statistics data, stems largely from the fall in mortgage repayments after a series of interest rate cuts.
If the RPI is negative it would be the first time the index has declined since March 1960. This is largely down to the fall in mortgage repayments after a succession of interest rate cuts.
The Bank of England uses the index of consumer prices (CPI) to set interest rates.
The latest RPI data showed prices had increased by just 0.1% in January compared with the previous year, the ONS said last month.
The Bank of England and UK government use the index of consumer prices (CPI) to target the level of inflation they desire.
But the government uses the broader measure of RPI to set the level of state pensions, welfare benefits and index-linked government bonds.
But the government uses the broader measure of RPI to set the level of state pensions, welfare benefits and index-linked government bonds.
Deflation explained
If the RPI measure of inflation is negative it will raise the prospect of deflation - regarded as a sustained period of falling prices.
Deflation is generally considered undesirable because people may stop spending as they wait for prices to go down further. This leads to a deflationary spiral, where prices and demand continue to fall and economic growth contracts.
This happened in Japan in the Nineties, when it experienced what it now known as its "lost decade".
There is also the concern of the cost of mortgage payments staying the same while other prices fall, effectively leading to an increased debt burden.
Economists surveyed by the UK Treasury expect retail prices to be falling by an annual rate of 1.9% by the end of the year.
The Bank of England said this month that periods of deflation would be "short-lived" if decisive action was taken using "more unconventional" monetary policy tools, such as so-called quantitative easing.
The Bank has slashed interest rates and has effectively increased the amount of money in the economy by £75bn in a bid to boost economic activity, which can cause prices to rise.
RPI-linked
Many annuities - a regular income from a retiree's pension pot - are also based on the yields made from government bonds or are linked directly to retail prices.
Regulated train fares, which account for 40% of all tickets sold, are also pegged to retail prices, with fares capped at 1% above retail price inflation, but the train companies are now arguing that formula was never designed for a period of deflation.
Regulated fares include season tickets and off-peak fares. Public sector unions also often refer to the RPI measure of inflation during wage negotiations.
These inflation figures will be the first using new items in the 650-strong basket of goods, which is updated every year.
The ONS announced on Monday that it has included such products as rotisserie chicken and rose wine, an indicator of the UK's changing spending habits.
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