A generation of youngsters are "paying the price" for the Government's austerity measures, the Children's Commissioner for England has warned.
Maggie Atkinson said the poorest families were being hit by welfare cuts, but children were also affected by library closures and reductions in spending on leisure facilities.
In an interview with Total Politics magazine the commissioner said local government cuts had also hit after-school and holiday clubs for children.
Dr Atkinson said Work and Pensions Secretary Iain Duncan Smith's welfare shake-up, part of the Government's efforts to cut the deficit and change the social security system to encourage people who can work to take a job, had "not served families well".
She said: "The poorest families, and therefore their children, are paying the price now. We did in-depth analysis on the welfare bill. Families, parents with children, especially where there was already economic pressure on the households, would be ill-served by the welfare reforms.
"I recognise, and our assessment recognises, that for some families Universal Credit would do good, would help them to make their money go further, but even with those effects we were adamant, and I remain adamant, that the welfare reforms have not served families well."
The commissioner said the impact of the Government's austerity measures on children were not confined to the welfare reforms.
She said: "Future generations coming down the line may well have a better time of it, but there are children now who are paying the price in England, not only for the reduction in welfare spending, but in libraries, in leisure facilities, in early intervention, in after-school clubs or holiday clubs.
"All of those things have been under such severe pressure in local government that many of them have stopped doing them. And that isn't just an urban issue."
Dr Atkinson also rejected London mayor Boris Johnson's call for children at risk of radicalisation from their parents to be taken into care to stop them being turned into ''potential killers or suicide bombers''.
The commissioner said: " Children who are in danger or at risk are in danger or at risk from a vast range of potential influences. The cases that have come to prominence, like Daniel Pelka, Victoria Climbie or Keanu Williams - the huge danger in their lives was about neglect, starvation, lack of care. I don't think you can possibly say every child who is in an ABC sort of household should be taken away.
"Professionals who do that sort of work do it on the basis of getting to know the family, getting to know the child, spending time working it out. They make decisions on the basis of a vast amount of evidence and it's never about one thing in that child's life.
"I don't think radicalisation, whether it's political or religious, any of the world's faiths or whatever, would be a sole reason for a professional to do something like that.
"It's subtler and more complicated than simply 'remove them and that will sort it', and it always is. That's why it's such a last-ditch decision - it's the biggest thing the state can do, to take a child away from its family. It's massive and not lightly should it be done."
A Department for Work and Pensions spokeswoman said: "Our reforms will improve the lives of some of the poorest families in our communities by promoting work and helping people to lift themselves out of poverty.
"Universal Credit will make three million households better off and lift up to 300,000 children out of poverty.
"There are a lot of misleading stories about our reforms, but the truth is that we spend £94 billion a year on working age benefits and the welfare system supports millions of people who are on low incomes or unemployed so they can meet their basic needs."