The official inquiry into Britain's role in the Iraq war is expected to contain severe criticism for former prime minister Tony Blair. Since the Allied forces first invaded in 2003, tens of thousands of Iraqis died in the conflict and the brutal sectarian war that followed.

Former Labour leader Tony Blair persuaded his cabinet and parliament to back the US-led invasion of Iraq on the basis of intelligence about Saddam Hussein's biological, nuclear and chemical weapons. 

"it concludes that Iraq has chemical and biological weapons. Saddam Hussein has continued to produce them that is actively trying to acquire nuclear weapons capability," said Tony Blair former British prime minister.

On February 5th, 2003, US Secretary of State Colin Powell addressed the United Nations General Assembly, continuing US efforts to gain UN authorization for an invasion. 

His presentation to the UN Security Council contained a computer-generated image of a 'mobile biological weapons laboratory'. 

"Indeed, the facts that Iraq's behaviour showed Saddam Hussein and his regime are concealing their efforts to produce more weapons of mass destruction," said Colin Powell former US Secretary of State.

Then US President George W. Bush declared war against Iraq a month later on March 19th, 2003.

"The people of the United States and our friends and allies will not live at the mercy of an outlaw regime that threatens the peace with weapons of mass murder. We will meet that threat now with our army, air force, navy, coastguard and marines," said George W. Bush former US President.

The US-led conflict killed over 170 British troops and some 4,500 American personnel. 

It also helped trigger violence that killed hundreds of thousands of Iraqis and still rocks the Middle East. 

"And it is true that much of the intelligence turned out to be wrong. As president, I am responsible for the decision to go into Iraq," said George W. Bush former US President.

In a CNN interview last year, "I apologise for the fact that the intelligence we received was wrong. I also apologise for some of the mistakes in planning and, certainly, our mistake in our understanding of what would happen once you removed the regime," said Tony Blair former British prime minister.

In April this year, the current US Democratic presidential front-runner Hillary Clinton revealed her biggest political regret--having voted in favor of invading Iraq in 2003.

"My greatest regret was voting to give president Bush authority in Iraq. It did not turn out way that I thought it would based on what he had said and I regret that and I' ve said it was a mistake obviously it's something that I wish hadn't turn out the way it did," said Hillary Clinton former US Secretary of State.

Another deadly attack took place recently in a Baghdad marketplace. The mistakes made before the invasion are still having a disastrous effect.