Saddam Hussein "would have posed a threat as long as he was in power", Tony Blair said.
The former prime minister said if Hussein had not been toppled he would have contributed to the Arab revolution in 2011.
"The world is a better place without Saddam. I believe it was the right thing to do."
Blair added that it would have been hard to assemble forces at a later date, and that Saddam Hussein would have had a stronger position. He continued that in this stronger position the Iraqi dictator would have gone on to develop nuclear and chemical weapons.
Alex Salmond told Peston on Sunday that he was backing the motion because a "verdict" on Blair was needed.
The long-awaited publication of the Chilcot report has raised many questions - we take a look at some of the key issues.
Thursday morning's newspapers were no less critical of Tony Blair than Sir John Chilcot's report into the Iraq war itself.