Jeremy Corbyn has condemned the decision to go to war in Iraq in 2003 as an "act of military aggression launched on a false pretext", as he was heckled by his own MPs.
Speaking to a full chamber in the House of Commons after Prime Minister's Questions, the Labour leader said the invasion and occupation of the country was a "catastrophe" as he responded to the findings of the long-awaited report.
Corbyn was a fierce critic of the Iraq War, having previously described the action as "illegal". And today he reiterated his stance as he hit out at the decisions which led to the UK going to war.
But Labour MPs - including Ian Austin - voiced their displeasure at Corbyn's statement as he spoke.
Corbyn said the invasion had "fostered a lethal sectarianism" that turned into a civil war: "Instead of protecting security at home or abroad, the war fuelled and spread terrorism across the region."
David Cameron said in his statement that MPs who voted to invade Iraq should take their "fair share" of the responsibility and announced that a two-day debate would be held next week.
Cameron said it should only ever be a "last resort" to go to war - but suggested that no government can guarantee military success, even if questions surrounding "machinery of government, proper processes, culture and planning" have been answered.
He said: "On Libya I believe it was right to intervene to stop Gaddafi slaughtering his people.
"In that case we did have a United Nations Security Council resolution, we did have proper processes, we did have comprehensive advice on all the key issues and we didn't put our forces on the ground. Instead, we worked with a transitional Libyan government.
"But getting these things right doesn't make the challenges of intervention any less formidable and the difficulties in Libya are plain for everybody to see today."
He also said that MPs should remember "violent Islamist extremism, al Qaida and all of that, started long before the Iraq War".