The Chilcot Inquiry into Britain's involvement in the 2003 Iraq War is due to be published on Wednesday (6 July), after a seven-year investigation. Under scrutiny is Tony Blair, the prime minister who took Britain into the conflict, and a number of his advisers such as Jack Straw, Alastair Campbell, and Sir Richard Dearlove.

There have been few leaks in the months leading up to the report's release, but while no-one is sure of what the report will say, there has been plenty of speculation about what it could contain.

The investigation – officially called 'The Iraq Inquiry' – was set up in 2009, by then Prime Minister Gordon Brown, to examine the circumstances under which Britain was taken into the war, including whether, and if so how, the public was misled about Iraq's military capabilities.

At the start of the inquiry Sir John Chilcot, the inquiry's chair, said it would examine the British government's, military's and intelligence services' actions between the "summer of 2001", during the run-up to the 2003 invasion, "to the end of July 2009", when British forces left Iraq as part of the withdrawal of Coalition forces.

Over the course of the war and subsequent occupation of Iraq, 179 members of the British armed forces were killed and 312 were injured.

The number of civilian casualties is widely disputed, but the independent Iraqi Body Count project estimates that 7,419 non-combatants were killed in the initial invasion, primarily by US forces, and a further 108,858 were killed during the start of the occupation by Coalition forces and March 2016.

If former Labour Leader Blair is accused of war crimes – most likely if the report suggests he was responsible for manipulating evidence of Saddam Hussein's desire and Iraq's military preparations to attack the West, contained in the notorious 'dodgy dossier' – it is unclear whether he will stand trial.

The International Criminal Court has said that while its prosecutors would investigate the report for claims of abuse and torture perpetrated by British soldiers, the decision to go to war in the first place lies outside its remit. A representative of the court told the Telegraph: "As already indicated by the Office in 2006, the 'decision by the UK to go to war in Iraq falls outside the Court's jurisdiction'."

Blair, speaking on 3 July, refused to discuss the suggestion that he might be arrested following the publication of the report, telling Sky News, "I think it's best we wait for Wednesday."

The report runs to 2.6 million words and is expected to hammer a number of Blair's key advisers who worked with him during the run-up to the declaration of war. Jack Straw, then home secretary, is expected to come in for strident criticism, as are a number of senior generals, Blair's spin doctor Alastair Campbell and Sir Richard Dearlove, who was head of the Secret Intelligence Service (MI6) at the time. Some commentators believe whole sections of Whitehall could be found partially culpable.

The report is also expected to address the so-called Crawford Ranch conversation between Blair and then US president George W Bush, which is said to have taken place in 2002 and which some claim is when the UK leader agreed to back the US president in a decision to go to war.

Alastair Campbell is a regular contributor for International Business Times UK.