Poor families have seen their benefits double in real terms over the last 30 years, according to new research.

State support for families with children has risen dramatically in the last four years.

Total welfare levels have reached £22 billion, according to a report commissioned by the Joseph Rowntree Foundation.

The research, conducted by the Institute for Fiscal Studies, concluded that successive governments have made inroads into tackling child poverty.

But the unit also concluded that the expansion of means-tested programmes and the creation of the Child Tax Credit mean the key Child Benefit - which goes to all parents - is no longer as important as it once was to families' finances.

The study found that in the 1970s benefits were delivered through tax allowances for working fathers.

Support is now given to mothers in two parent families who are seen as the main carers.

It also concluded that the tax system re-emerged after 1999 as the main delivery for cash through the introduction of the Child Tax Credit.

"Parents are now receiving much more financial support from the state to help them bring up their children than at any time in the past 30 years, with much of the increase occurring under the current government," said Mike Brewer of the Institute for Fiscal Studies.

"But if policy makers wish to use the costs of raising children as a guide to setting levels of financial support for children, we need to understand better how these costs vary across different sorts of families and change over time."