Archbishop of Canterbury Rowan Williams, echoing growing unease over debt-ridden Britain, said on Friday the poor are being crippled by personal debt and called for greater scrutiny of "doorstep" loan companies.

The spiritual leader of the world's 77 million Anglicans, launching into a moral debate about the victims of the credit crunch, attacked excessive interest rates charged to the most vulnerable.

"We need to look at what it means for a whole economy to be built up on spiralling, more or less uncontrolled credit," Williams told BBC Radio.

The British have amassed nearly 1.5 trillion pounds of debt, putting them among the world's biggest borrowers.

Most of the debt in Britain's house-owning society is sunk into mortgages and there are growing fears the credit crunch will leave many exposed to bankruptcy if house prices plummet as some analysts fear.

Williams, reflecting on an increasingly secular society where consumerism is king, said he feared the poor are now trapped in a cycle of unsecured borrowing, with children most at risk of being the biggest losers in an economic downturn.

"My immediate concern today is looking at the bottom of the ladder and the way in which the credit crunch impacts so disproportionately on the most disadvantaged," he added.

The credit crunch has made getting hold of cash more expensive on financial markets and those higher costs have been passed on to consumers - hitting the poorest the hardest as they struggle to stay afloat.

"One of the things I would really want to see as a matter of urgency reviewed here is the interest rates charged by some doorstep lending companies," Williams said.

Arguing that advertising standards should be reviewed, he said: "There is the need for the teaching of financial literacy.

"People often don't understand what the rates of interest might be. They can find themselves being charged over 1,000 percent in a couple of years' time with rollover debts."