Former prime minister Sir Tony Blair has admitted he “may have been wrong” about the decision to invade Iraq and Afghanistan, but insisted he thought it was “the right thing” to do.

Speaking to the Archbishop of Canterbury Justin Welby as part of BBC Radio 4’s The Archbishop Interviews series, Sir Tony defended his decision to intervene in the Middle East alongside former US president George W Bush.

“People often say over Iraq or Afghanistan that I took the wrong decision but you’ve got to do what you think is right,” the 68-year-old said.

“Whether you are right or not is another matter. In those really big decisions you don’t know what all the different component elements are, and you’ve got to follow, in the end, your own instinct.”

He added that although his decision “may have been wrong”, he “had to do what I thought was the right thing”.

Sir Tony was appointed a Knight Companion of the Most Noble Order of the Garter, the oldest and most senior British Order of Chivalry, in the New Year’s honours list.

However, a Change.org petition to strip him of his knighthood gathered more than one million signatures.

The petition said: “Tony Blair caused irreparable damage to both the constitution of the United Kingdom and to the very fabric of the nation’s society.

“He was personally responsible for causing the death of countless innocent civilian lives and servicemen in various conflicts. For this alone he should be held accountable for war crimes.

“Tony Blair is the least deserving person of any public honour, particularly anything awarded by Her Majesty the Queen.”