Britain is the worst country in the industrialized world in which to be a child, the United Nations Children's Fund ( UNICEF) said.

The charity looked at 40 indicators to gauge the lives of children in 21 economically advanced nations -- the first study of its kind -- and found Britain's children were among the poorest and most neglected.

Children's charities and opposition politicians described the findings as "shameful" and accused Prime Minister Tony Blair's government of failing a generation of children.

Britain lagged behind on key measures of poverty and deprivation, happiness, relationships, and risky or bad behavior, the study showed.

It scored a little better for education but languished in the bottom third for all other measures, giving it the lowest overall placing, along with the United States.

Children's happiness was rated highest in northern Europe, with the Netherlands, Sweden and Denmark leading the list.

"All countries have weaknesses that need to be addressed and no country features in the top third of the rankings for all six dimensions," said David Bull, UNICEF UK's executive director.

The study found there was no consistent relationship between a country's wealth, as measured in gross domestic product per capita, and a child's quality of life.

The Czech Republic, for example, achieved a higher overall ranking than economically wealthier France.

'SHAMEFUL'

Colette Marshall, UK director of charity Save the Children, said the report was a "shameful" verdict on Britain.

"Despite the UK's wealth, we are failing to give children the best possible start in life," she said in a statement.

She said "drastic action," including an injection of 4.5 billion pounds, was needed to meet a government target of halving the number of children in poverty by 2010.

A government spokeswoman said the data in the report -- mainly taken from 2000 to 2003 -- was not up to date and that reforms introduced through the "Every Child Matters" initiative had improved child welfare.

There were 700,000 fewer children living in relative poverty than in 1998/99, and the overall number living in absolute poverty had been halved, she said.

But the Child Poverty Action Group said the report was "an important reminder that we need to go further, faster" and the chief executive of the Children's Society, Bob Reitemeier, described it as "very worrying" for Britain.

George Osborne, Treasury spokesman for the opposition Conservative Party, said the report was a damning indictment of the policies of Blair and his finance minister and likely successor Gordon Brown.

"After ten years of his welfare and education policies, our children today have the lowest well-being in the developed world," he said. Brown had "failed this generation of children and will fail the next if he's given a chance," Osborne said.