A former top judge says legal advice given to Tony Blair before the invasion of Iraq was "flawed".

Lord Bingham, who stepped down in July, has questioned the actions of the US and UK.

He said there was a lack of hard evidence to justify the conflict.

In a speech on the rule of law at the British Institute of International and Comparative Law, Lord Bingham referred to a statement made by the former attorney general Lord Goldsmith in March 2003 as Britain prepared for the invasion.

"This statement was flawed in two fundamental respects," he said.

"It was not plain that Iraq had failed to comply in a manner justifying resort to force and there were no strong factual grounds or hard evidence to show that it had.

"Hans Blix and his team of weapons inspectors had found no weapons of mass destruction, were making progress and expected to complete their task in a matter of months."

Lord Bingham added that Lord Goldsmith's advice passed on the belief that a decision over whether Iraq had not complied with UN resolutions could be made by anyone other than the UN Security Council.

He said: "If I am right that the invasion of Iraq by the US, the UK and some other states was unauthorised by the Security Council there was, of course, a serious violation of international law and of the rule of law."

Responding to the criticism, Lord Goldsmith said: "I stand by my advice of March 2003 that it was legal for Britain to take military action in Iraq.

"I would not have given that advice if it were not genuinely my view. Lord Bingham is entitled to his own legal perspective five years after the event, but at the time and since then many nations other than ours took part in the action and did so believing that they were acting lawfully."

He added that the UN resolution that Iraq was deemed to have failed to comply with, and which ultimately led to the invasion, did not need further determination by the Security Council.

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