In his surprise remarks, Denis Halliday, said his 13-month stint had taught him the "damage and futility" of sanctions.

Halliday: Thousands of children are dying

''It doesn't impact on governance effectively and instead it damages the innocent people of the country,'' he told Reuters news agency.

"It probably strengthens the leadership and further weakens the people of the country.''

Mr Halliday, who has resigned after more than 30 years with the United Nations, leaves his post in Baghdad on Wednesday.

He was co-ordinator of the programme that allows Iraq to sell limited amounts of oil to buy food, medicine and other supplies.

He said maintaining the crippling trade embargo imposed on Iraq for its 1990 invasion of Kuwait was incompatible with the UN charter as well as UN conventions on human rights and the rights of the child.

But Mr Halliday believed UN Secretary-General Kofi Annan favoured a fresh look at sanctions as a means of influencing states to change their policies - in Iraq's case making it scrap its weapons of mass destruction, and long-range missiles.

"I'm beginning to see a change in the thinking of the United Nations, the secretary-general, many of the member states, who have realised through Iraq in particular that sanctions are a failure and the price you extract for sanctions is unacceptably high.''

His comments follow criticism recently by a top UN weapons inspector, Scott Ritter, of the US and UK for failing to take a tougher line over the inspections.

Up to 5,000 children dying a month

Mr Halliday said disarmament was a legitimate aim, but took issue with the "open-ended" and politicised nature of weapons searches in Iraq.

"There is an awful incompatibility here, which I can't quite deal with myself. I just note that I feel extremely uncomfortable flying the UN flag, being part of the UN system here," he added.

Mr Halliday said it was correct to draw attention to the "4,000 to 5,000 children dying unnecessarily every month due to the impact of sanctions because of the breakdown of water and sanitation, inadequate diet and the bad internal health situation".

A baby's coffin paraded in a protest against sanctions

But he said sanctions were biting into the fabric of Iraqi society in other, less visible ways.

He cited the disruption of family life caused by the departure overseas of two to three million Iraqi professionals.

He said sanctions had increased divorces and reduced the number of marriages because young couples could not afford to wed.

"It has also produced a new level of crime, street children, possibly even an increase in prostitution," he said.

"This is a town where people used to leave the key in the front door, leave their cars unlocked, where crime was almost unknown. We have, through the sanctions, really disrupted this quality of life, the standard of behaviour that was common in Iraq before."

Young Iraqis likened to Taleban

Mr Halliday argued that the "alienation and isolation of the younger Iraqi generation of leadership" did not bode well for the future.

Women queue for food

He said many senior government figures had been trained in the West and exposed to the outside world.

Their children had stayed at home through the 1980-88 Iran-Iraq war, the 1991 Gulf War and now sanctions.

"They don't have a great deal of exposure to travel, even to reading materials, television, never mind technological change," he said.

"I think these people are going to have a real problem in terms of how to deal with the world in the near future."

Likening their introverted development to that of Afghanistan's Taleban movement, Mr Halliday said younger Iraqis were intolerant of what they considered their leaders' excessive moderation.

Mr Halliday noted mosque attendance had soared during the sanctions era as people sought solace in religion - a change from Iraq's hitherto largely secular colouring.

"What should be of concern is the possibility at least of more fundamentalist Islamic thinking developing," he said.

"It is not well understood as a possible spin-off of the sanctions regime. We are pushing people to take extreme positions."