As stated in “The Report of the Iraq Inquiry – Executive Summary”: “21. In mid-March, Mr Blair’s determination to stand alongside the US left the UK with a stark choice. It could act with the US but without the support of the majority of the Security Council in taking military action if Saddam Hussein did not accept the US ultimatum giving him 48 hours to leave. Or it could choose not to join US-led military action. Led by Mr Blair, the UK Government chose to support military action. Mr Blair asked Parliament to endorse a decision to invade and occupy a sovereign nation, without the support of a Security Council resolution explicitly authorising the use of force. Parliament endorsed that choice.”
– Commissioned by the Prime Minister The Right Honourable Gordon Brown MP, “The Report of the Iraq Inquiry: Executive Summary,” IraqInquiry.org.uk, March 15, 2003