By Alex Kirby BBC News Online environment correspondent

A former United Nations official who worked in Iraq says he does not believe it possesses weapons of mass destruction.

The official, Denis Halliday, was the UN humanitarian co-ordinator in Iraq in 1997-98.

Mr Halliday said he thought a US attack on Iraq was likely later this year, and people there were deeply concerned.

Any attack could mean appalling losses of Iraqi civilians and US troops.

Mr Halliday worked for the UN for 34 years, and was an assistant secretary-general when he was sent to Baghdad.

But he resigned from the UN to have the freedom to criticise the international sanctions policy directed at Iraq.

Bombs in prime time

In an interview with BBC News Online, Mr Halliday said: "I don't think Saddam Hussein possesses any weapons of mass destruction.

"There'd be no doomsday option for him in the event of a US attack. But it could mean horrific casualties among Iraqis, who I think would fight, and for the Americans.

Iraqis "will resist any attack"

"I think we'll probably see the Americans bombing Iraq before their November elections. An invasion could come early next year."

Mr Halliday was scathing about the present UN, which he said many people in Europe and the Middle East now regarded as effectively part of the US State Department.

"The removal of Boutros Boutros-Ghali, the last secretary-general, was an outrageous undermining of the UN," he said.

"He had courage and guts - he was independent. But Kofi Annan was handpicked as his successor because he was seen as friendly to the US.

It's Blair, Schroeder and Chirac who'll change George Bush's mind, not Osama bin Laden

Denis Halliday

"Mr Annan has squandered his opportunities to stand up and be counted.

"He hasn't used his moral authority, for example by using Article 99 of the UN Charter to draw matters of concern to the Security Council's attention. He could have got them to discuss the Rwandan genocide, or Chechnya, but he didn't."

Mr Halliday, an Irish citizen, lives in the US, and says he is not anti-American.

The silent friend

"There are some good people in Washington who realise that rejecting international law is not in the US' own long-term interests," he said.

"But rejection is what the administration is about - the Kyoto Protocol on climate change, the land mines convention, the international criminal court, and so on.

Sanctions "are killing Iraqi children"

"The only way to change the US is through its friends, not its enemies.

"It's Blair, Schroeder and Chirac who'll change George Bush's mind, not Osama bin Laden.

"I'd like to see Tony Blair nominated for the Nobel Peace Prize if he could influence US foreign policy towards non-aggressive goals.

Voice of the poor

"But he's silent, he has this habit of disappearing. What's the point of having access and influence if you don't use them?"

Mr Halliday argues that "a sole hyper-power is dangerous", but does not want to return to a world where two great blocs confronted each other.

"A balance of power is very important", he said. "But that won't come from confrontation.

"We have to reform the Security Council. At present it's an old boys' club of the world's major arms traders.

"It needs a permanent voice from the developing world, and probably only one European Union member. So either France or the UK should go."