Archbishop Desmond Tutu of South Africa has called for former British Prime Minister Tony Blair and the former United States President George Bush to face criminal action for their roles in the war in Iraq.
Writing in The Observer newspaper on Sunday, he accused them of lying about weapons of mass destruction.
The Iraq military campaign had made the world more unstable "than any other conflict in history", he said.
He said they lied about Iraq having weapons of mass destruction and should be brought before the International Criminal Court to answer for the many deaths caused by the conflict.
Mr Blair dismissed the remarks as baseless and nothing new.
"I have a great respect for Archbishop Tutu's fight against apartheid,'' he said, ''but to repeat the old canard that we lied about the intelligence is completely wrong as every single independent analysis of the evidence has shown.
"And to say that the fact that Saddam massacred hundreds of thousands of his citizens is irrelevant to the morality of removing him is bizarre."