One in five British children live below the poverty line, new research has revealed.
The Campaign to End Child Poverty published figures on Wednesday showing that 20.2% of British children are classified as below the poverty line before housing costs.
In eight areas of large cities, over four out of every 10 children lived in poverty in 2012, the research showed.
But that is a decrease on the 19 parliamentary constituencies that had 40% of children living in poverty in 2011.
The poorest constituency for children was Manchester Central, with nearly half (47%) of children living in poverty.
Over four in 10 children were living in poverty in Belfast West (43%), Glasgow North East (43%), Ladywood, Birmingham (42%), Liverpool Riverside (42%), and Middlesbrough (40%).
In London, 40% of children were living in poverty in Tower Hamlets, 42% of children were below the poverty line in the constituency of Bethnal Green and Bow while 41% were living in poverty in Poplar and Limehouse.
The situation has broadly improved since 2011, except in some areas of the North East of England.
In Newcastle, 38% of children were poor in 2012, compared with 29% in 2011, while in Middlesbrough the figure rose to 40% from 38% in the previous year.
Child poverty was the lowest in deputy prime minister Nick Clegg's Sheffield Hallam constituency (below 5%).
It was also under 10% in prime minister David Cameron's Witney constituency, the report said.
The figures revealed the wide disparity in poverty rates across the UK and within regions.
For example, in London, Poplar and Limehouse has a child poverty rate of 41% compared to just 7% in Richmond.
In the North West, whereas 38% of children in the local authority area of Manchester are poor, in Ribble Valley the figure is just 7%.
In the figures, children are classified as being in poverty if they live in families receiving out of work benefits or in-work tax credits where their reported income is less than 60% of median income.
The report said: "This is not a direct measure of exactly how many children are in poverty on the official definition, but is the closest to an equivalent measure we have of local levels of child poverty (these data should therefore not be used for direct comparisons with official national and regional figures). The figures are estimates for mid-2012."
Enver Solomon, chair of the Campaign said: "The child poverty map reveals the depth and breadth of child poverty across the country showing the gross levels of inequality that children face in every region.
"Far too many children whose parents are struggling to make a living are having to go hungry and miss out on the essentials of a decent childhood that all young people should be entitled to.
"The huge disparities that exist across the country have become more entrenched and are now an enduring reality as many more children are set to become trapped in long term poverty and disadvantage.
"Local authorities are having to deal with reduced budgets but they have critical decisions to make.
"We're calling on authorities to prioritise low income families in the decisions they make about local welfare spending, including spending on the new council tax benefit, and on protecting families hit by the bedroom tax.
"This week we have written to local authority leaders in the local authorities with the most child poverty, asking them what they will do to tackle child poverty in their local area.
"The government must also closely examine its current strategy for reducing poverty and consider what more it could do to ensure millions of children's lives are not blighted by the corrosive impact that poverty has on their daily existence."
Rhian Beynon, of the support charity Family Action, said: "The government must explain urgently how it is going to address these devastating findings by the End Child Poverty Campaign. For every child counted poor by this report there is a parent struggling to keep a roof over their heads, the house warm and food on the table.
"But on top of this daily struggle their child faces worse prospects for their education, a job and health. We know that what makes a difference is a mixture of support from services and the welfare system and it is the Government which sends the most important signal on these policies to local authorities."
A Department for Work and Pensions spokeswoman said: "We are committed to eradicating child poverty, but we want to take a new approach by tackling the root causes including worklessness, educational failure and family breakdown.
"Our welfare reforms will improve the lives of some of the poorest families in our communities, with the Universal Credit simplifying the complex myriad of benefits and making three million people better off."