The report, published by the Office of the Children's Commissioner for England, argues that economic measures will hit families with children the hardest, resulting in another 600,000 children living in poverty over the next two years. It said its findings mean that the Government is at risk of not meeting its obligations to children and young people.
As a signatory to the UN Convention on the Rights of the Child, the UK Government is bound by international law to uphold children's rights to the maximum extent of available resources.
Work on the report, titled A Child Rights Impact Assessment of the 2013 Budget, was carried out by independent economists, to examine the full impact of Government policies and tax and benefit reforms. It found that that the biggest negative impacts of the Government's work to reduce the deficit will fall on families with children.
Single parents and those with disabled children are being particularly hard hit and the income of families with children has been reduced by over twice as much as similar families without children, the report found.
Families with children in the poorest 10% of the population are losing an average of £40 per week from the reforms with families in the lowest 20 and 30% losing an average of £30 per week. These losses represent a "very serious reduction" in income when the poorest families with children live off around £370 per week, the report said.
Universal Credit reforms that will be in place by 2015 will in part offset the impacts, but they will not cancel out all of the losses that families have seen since 2010, researchers said.
Maggie Atkinson, Children's Commissioner for England, described the report as the "most comprehensive and accurate analysis we have to date on what exactly is happening to the poorest and some of the most vulnerable members of society". She said: "It makes uncomfortable reading: they are getting progressively worse off and more children are entering poverty. Ultimately, that means more children going without the basics because their parents and carers cannot afford them."
The Children's Commissioner for England was set up as an independent voice to champion young people's interests and highlight their concerns.