Tony Blair has said there is "not a single day" where he doesn't think about the Iraq decision but he "had to take a decision that was really hard".
The former prime minister said he "thought really deeply" about the "hard decision".
"I go back over it all the time, all the time I relive it, all the time, there's not a single day I don't relive it."
Former foreign secretary Jack Straw has said that he will live with the consequences of the decision to go to war in Iraq "for the rest of my life."
Mr Straw added: "This is as nothing, however, compared with the grief of all those who lost loved ones in the conflict and its aftermath".
He continued, "with the benefit of hindsight, different decisions would have been made in Iraq".
The former Labour MP added that the decision to go to war in Iraq was "the most serious decision in which I was ever involved".
Confronted with information about weapons of mass destruction, Mr Straw insisted that he did not take the intelligence "at face value, but questioned those providing it about its accuracy and its provenance". Based on this, Mr Straw said he believed "military action was necessary", though he conceded this was not what the report had found.
Jeremy Corbyn may bow to pressure from MPs to step down as Labour leader after he accuses Tony Blair over his role in the Iraq war when the Chilcot inquiry report is published next week, Westminster sources suggested.
The beleaguered party chief has so far refused to go despite facing mass resignations from his cabinet in a full-scale revolt among the Labour parliamentary party.
However some believe that he may be holding out for a chance to confront the former Labour Prime minister Mr Blair when the long-awaited Chilcot report is published next Wednesday, reports ITV News Political Correspondent Carl Dinnen.
It's possible that once that big date is out of the way, he may reconsider his position.
The ex-prime minister said the referendum had expressed the will of the people but "the will of the people is entitled to change".Read the full story ›
Former British prime minister Tony Blair has warned that "our nation is in peril" after voting to leave the EU.
In an article in the Daily Telegraph, Blair urged contenders in the Tory leadership race to act with "genuine patriotic regard" to the country's future as he stated that "serious statesmanship" would be needed in the talks with the European Union.
Our nation is in peril. To allow us to come safely through this we need to be adult in our politics, to proceed with calm, maturity and without bitterness; because our future as a nation in the world and as the UK itself is at stake.
Tony Blair and Sir John Major have united to warn of the risks Brexit poses to the unity of the UK.Read the full story ›
The former prime minister said the Labour leader is more interested in the "politics of protest" than the "politics of power".Read the full story ›
The former prime minister suggested a Jeremy Corbyn government would be a 'very dangerous experiment'.Read the full story ›
Former prime minister said he failed to predict chaos after toppling of dictator as he calls for UK to send in ground troops against Isis.Read the full story ›