The ex-PM said his refusal to express regret for the decisions that led to war at his first appearance before the committee had been misinterpreted.
But his words were met with cries of “too late” from the public gallery.
Mr Blair also urged the West to stop apologising for its actions in Iraq and warned of the threat from Iran, during a four-hour grilling by the inquiry.
Asked whether what had happened in Iraq had made the risk from Iran and other countries developing nuclear weapons worse, rather than better, he said: “I don’t think so.”
