Against the backdrop of recent controversy over Planning Commission's poverty line, Prime Minister Manmohan Singh Thursday said gauging poverty is a "difficult task" as there are diverse views on the definition.

"Measuring poverty is a difficult task. There are diverse views about what constitutes poverty. But whatever definition we may adopt, it cannot be denied that the pace of reduction of poverty has increased after 2004," Singh said.

His comments, on the occasion of 67th Independence Day celebrations, came weeks after a major controversy over the way to define poverty.

The controversy erupted after Planning Commission said persons spending over Rs 33.33 a day in cities and Rs 27.20 in villages are not poor. Based on this, Commission concluded that the poverty ratio in the country declined to 21.9 per cent in 2011-12 from 37.2 per cent in 2004-05.

The parameters used by the Planning Commission to define poverty were criticised by Opposition as well as constituents of the ruling alliance saying the figures were unrealistic.

Singh's Cabinet colleague, Finance Minister P Chidambaram in Rajya Sabha yesterday said that about a 140 million people have been "lifted above the poverty line" during the UPA regime.

"Our claim actually is, we have lifted about 140 million people. Wherever you draw the line...You take the poverty-wise population, you take the income-wise population, stratify if, draw the line anywhere you like.

"Draw the line anywhere at two dollars, at three dollars and then, what was the population below that line 10 years ago, what is the population below that line today...The difference is about 140 million people," Chidambaram had said.