Poverty measuring change to be announced by Iain Duncan Smith

The Government is to draw up plans to change the way poverty is measured in a move that will trigger claims that it is trying to mask a rise in the number of poor families.

Iain Duncan Smith, the Work and Pensions Secretary, will announce today that he intends to abolish the traditional definition that a family with an income of less than 60 per cent of the median is in poverty.

Mr Duncan Smith will say: "The Government is very interested in developing better measurements of child poverty, which include income but do more to reflect the reality of child poverty in the UK today."

He will point out that giving a family just below the poverty line £1 a week could technically move them out of poverty. But income from welfare transfers could end if nothing changed – for example, if the parents suffer from drug addiction.

Independent analysts predict poverty will rise because of spending cuts and the flatlining economy, but Mr Duncan Smith will insist the Coalition remains committed to Labour's target to abolish child poverty by 2020. Official figures out today will show whether Labour met its goal to halve it by 2010.