The Government's new draft child poverty strategy has been branded "a serious missed opportunity" by David Cameron's social mobility tsar Alan Milburn.
Work and Pensions Secretary Iain Duncan Smith's failure to reach agreement with Chancellor George Osborne over his plan to rewrite the official definition of policy was "beyond Whitehall farce", said Mr Milburn, who urged ministers to go back to the drawing board.
The strategy, which was released for consultation by Mr Duncan Smith in a written statement to Parliament, restates the Government's commitment to end child poverty by 2020 and promises to "tackle poverty at its source" but contains no new policy proposals to help the poorest families.
After reportedly clashing with Mr Osborne over his heavily-trailed plans to rewrite the definition of poverty to include factors like educational opportunity, worklessness and parental addiction, Mr Duncan Smith has agreed to put the idea on hold, saying in a joint article with the Chancellor that "this is such an important issue - it is vitally important that we take the time to get it right".
The new document lists a range of existing policies across Government which might help children living in poverty over the coming three years, from support for childcare to free school meals, discounts on energy bills and increases in the threshold for paying income tax.
Mr Duncan Smith said that the strategy focuses on the "underlying causes" of poverty, such as worklessness, and his Department of Work and Pensions (DWP) highlighted the reduction to 274,000 in the number of children living in workless households - the lowest on record.
The DWP said that academic evidence published alongside the strategy showed it was possible to "confidently conclude" that t he key factor for child poverty now is parental worklessness, with other main factors including low parental qualifications, parental ill health, family instability and family size, and that the most influential factor increasing the risk that a poor child will grow up to be a poor adult is educational attainment.
But Mr Milburn, the c hairman of the Government's Social Mobility and Child Poverty Commission (SMCPC), said that the strategy "sidestepped" the fact that the situation on poverty has been "stagnating", with independent projections that it will rise significantly by the end of the decade.
"Two-thirds of child poverty is now found in working households. In three-quarters of those families, someone works full-time. That is why we called for the new child poverty strategy to deliver an ambitious detailed step-by-step plan for how the Government will meet the 2020 targets," wrote Mr Milburn in a blog on the SMCPC website.
Instead, he said the new document was "a list, not a strategy" which failed to engage with expectations that the 2020 target to eradicate child poverty "will be missed by a country mile" and lacked any measures against which the Government can be held to account. The strategy should be "far stronger on some central issues like low pay and childcare", he said.
"A strategy which cannot be measured is meaningless," said Mr Milburn. "Despite taking more than a year to think about it, the Government has drawn a blank, apparently unable to reach agreement on what a new set of measures should look like.
"The Government has ended up in a no-man's land where it has effectively declared its lack of faith in the current measures but has failed to produce an alternative set. This is beyond Whitehall farce.
"Ministers should get back to the table to decide whether the Government will either reaffirm its commitment to the current statutory measures or propose new and additional measures to supplement the existing framework. They should do so immediately and set a deadline of no more than one month to reach agreement."
Labour pointed to figures from the independent Institute for Fiscal Studies showing that relative child poverty - based on the Government's current definition - has increased from 2.3 million in in 2011/12 and is forecast to rise further to 3.2 million in 2020/21, nearly reversing a fall of one million under the previous administration.
Shadow work and pensions secretary Rachel Reeves said: "Child poverty is set to rise by 400,000 under David Cameron's Government, while ministers squabble over the way poverty is defined.
"The row between George Osborne and Iain Duncan Smith does nothing to help working people who are £1,600 worse off a year because of the cost-of-living crisis.
"If David Cameron was serious about cutting child poverty he would scrap the Bedroom Tax, introduce a compulsory jobs guarantee, strengthen the Minimum Wage, incentivise the living wage and extend free childcare for working parents."
Mr Duncan Smith said: "At the heart of our welfare reforms is the commitment to transform the lives of the poorest and most disadvantaged in our society. Central to our approach is the conviction that it is not enough only to tackle the symptoms of poverty without also tackling the underlying causes.
"Today, with the launch of our consultation on the new child poverty strategy, we restate our commitment to tackling poverty at its source - be it worklessness, family breakdown, educational failure, addiction, or debt. These are the problems that blight the lives of vulnerable families and the strategy draws together the action we are taking on all these fronts."
The strategy was welcomed as "a step in the right direction" by two Church of England bishops who have previously spoken out on child poverty issues.
Bishop of Leicester Tim Stevens and Bishop of Birmingham David Urquhart said in a joint statement: "We welcome the Government's firm commitment to ending child poverty by 2020. The measures announced in this paper are a step in the right direction, though much more will need to be done to enable us to come close to achieving this very ambitious target.
"As the economy recovers we encourage the Government to pursue policies to ensure that the proceeds of growth will be shared by low income families with children, and by other groups that have been most adversely affected by the recession."
Child poverty charities and campaigners gave the draft strategy a chilly reception.
Matthew Reed, chief executive of The Children's Society, said: "The Government's continued commitment to ending child poverty is welcome. But its strategy has no new ideas on how to make this a reality. It falls far short of what is needed to prevent a significant increase in the number of children living in poverty by 2020.
"Too many of the strategy's measures will fail to end child poverty. Some will make the problem worse."
The chief executive of families charity 4Children, Anne Longfield, said: "The current plans for the new child poverty strategy lacks the vision or the means which are needed to eradicate child poverty.
"Focusing on getting parents back into work is important but, at present, most of those in poverty are working and the stark reality is that some parents can be worse off in work than being unemployed.
"Families living in poverty are often facing a number of issues, for example ill-health, or a parent with an alcohol or drug addiction. These must not be treated in isolation - comprehensive and tailored support is needed for the whole family to lift them out of poverty and we need a new commitment to families."
Chris Goulden, head of poverty research at the Joseph Rowntree Foundation, said the charity was "disappointed" that ministers had failed to reach agreement on child poverty measures.
" With one in four families expected to be in poverty by 2020, a renewed strategy to address child poverty is vital," said Mr Goulden. "Any effective strategy should be based on evidence and contain measures to reduce the cost of living and improve family incomes.
"However, until those measures are agreed, it is difficult to see how the Government can move forward."
Downing Street insisted that child poverty had fallen since the coalition took power in 2010.
The Prime Minister's official spokesman said: " Under the principal measure that was set out in the pre-May 2010 legislation, I think child poverty is down 300,000 on that measure.
"We see record levels of employment and we need to keep at the things that help encourage employment because work is the best route out of poverty."
David Holmes, who chairs the End Child Poverty campaign, said: "It surely has to be one of the highest priorities for any government to protect our children from poverty so we welcome the Government's commitment to breaking the cycle of disadvantage and preventing poor children becoming poor adults.
"The Government has said today that it remains committed to maintaining the goal of ending child poverty in the UK by 2020. We are concerned that this draft strategy as it stands falls short of what is required to guarantee a reduction in child poverty and is just not radical enough to meet the goal of ending child poverty.
"Tackling child poverty requires bold action across Government and across wider society, for example to tackle low pay, unaffordable rents and crippling childcare costs.
"We look forward to providing a detailed response to this consultation and to working with Government to strengthen the strategy. A generation of children are depending on us to get this right."
Citizens Advice chief executive Gillian Guy said: "A four-year process which produces nothing concrete is unacceptable. The people living on a knife-edge who come to Citizens Advice Bureaux for help are not interested in how Whitehall defines their circumstances - they are too busy working out how they will put food on the table. The struggle of millions of people to make ends meet should have spurred ministers into urgent action, not slowed their response to a snail's pace."
Barnardo's assistant director of research and policy, Neera Sharma, said: " With over 5 million UK children set to grow up poor by 2020, we need major surgery to tackle poverty, not the sticking-plaster solutions offered by the Government today.
"To avert the impending poverty crisis the Government needs to focus its resources on new policies that would have an immediate and long-term impact on hardship. They can start by bringing down high childcare costs to make work pay for the poorest, whilst urgently reviewing welfare reform measures that plunge more children into poverty."
Matthew Downie, head of campaigns and public affairs at Action For Children, said: "Child poverty is becoming more about politics and less about children.
"While the Coalition continues to argue about the definition of poverty, under its existing obligations the numbers of children below the breadline is set to rise to 4.7 million by 2020. It's important that politicians agree on the right definition of poverty but not at the expense of families who need help now."
Fiona Weir, chief executive of single parent charity Gingerbread, said: "Money matters, and quick fixes ring hollow alongside existing policies that are cutting family incomes, increasing poverty and doing long-term damage to children's life chances.
"Rather than Universal Credit being a panacea for in-work poverty, research shows that working single parents will be the biggest financial losers under the new system. Much more needs to be done to make work pay - starting with increasing support for childcare costs to 85% for all working parents."
The general secretary of the Association of Teachers and Lecturers, Mary Bousted, said: " Iain Duncan Smith's belief that education is a way out of poverty is mistaken. It is not that simple. Teachers' experience is that poverty restricts the ability of children to learn and research shows that schools can have only a limited effect on the achievement of children from disadvantaged backgrounds."
Chris Keates, general secretary of the teaching union NASUWT, said: "However this coalition Government chooses to dress it up, its social and economic policies are driving up child poverty. A few giveaways around food vouchers and small reductions in utility bills will not address the scandal of child poverty in the UK."
William Higham, Save the Children director of UK poverty policy, said: "Today's debate about child poverty has generated far more heat than light. In all the political positioning the horrific impact of poverty on children's lives has been neither seen nor heard.
"The families we work with around the UK tell us the same thing; child poverty getting worse at the harsh end and many more families living on a knife edge."