John Prescott, number two in the Labour government when Britain took part in the US-led invasion in 2003, made the remarks in a piece to be published in the Sunday Mirror newspaper.
On Wednesday, the Chilcot report returned a damning verdict on Britain’s role in the US-led war, finding it joined the conflict before all peaceful options had been exhausted and that judgments about Iraq’s capacities were “presented with a certainty that was not justified.”
It also disclosed Blair had written to then US president George W. Bush that “I will be with you, whatever” eight months before the invasion.
Prescott, now a member of the House of Lords, wrote: “I will live with the decision of going to war and its catastrophic consequences for the rest of my life.
“In 2004, the UN secretary-general Kofi Annan said that as regime change was the prime aim of the Iraq war, it was illegal.
Former British Prime Minister Tony Blair addresses a news conference in London on July 6, 2016, following the release of the Iraq Inquiry report. (Stefan Rousseau/Pool/AFP)
“With great sadness and anger, I now believe him to be right.”
Blair this week voiced “sorrow, regret and apology” over mistakes made in the conflict.
But he insisted the war was right and the world was safer without toppled Iraqi dictator Saddam Hussein.