Breaking with the official White House position, Pentagon official Richard Perle yesterday acknowledged that the U.S. invasion of Iraq was illegal.

In a startling break with the official White House and Downing Street lines, Mr Perle told an audience in London: "I think in this case international law stood in the way of doing the right thing."

....Mr Perle, a key member of the defence policy board, which advises the US defence secretary, Donald Rumsfeld, said that "international law ... would have required us to leave Saddam Hussein alone", and this would have been morally unacceptable.

....Mr Perle's view is not the official one put forward by the White House. Its main argument has been that the invasion was justified under the UN charter, which guarantees the right of each state to self-defence, including pre-emptive self-defence. On the night bombing began, in March, Mr Bush reiterated America's "sovereign authority to use force" to defeat the threat from Baghdad.