It was initially established by Prime Minister Gordon Brown that the Iraq Inquiry would be held in camera, excluding the public and press.

[10] In the week before the inquiry began hearing witnesses, a series of documents including military reports were leaked to a newspaper which appeared to show poor post-war planning and lack of provisions.

It covered the run-up to the conflict, the subsequent military action and its aftermath to establish how decisions were made, to determine what happened and to identify lessons to ensure that, in a similar situation in future, the British government is equipped to respond in the most effective manner in the best interests of the country.

In 2012, the government vetoed the release to the inquiry of documents detailing minutes of Cabinet meetings in the days leading up to the invasion of Iraq in 2003.

Concurrently, the Foreign Office successfully appealed against a judge's ruling and blocked the disclosure of extracts of a conversation between George W. Bush and Tony Blair days before the invasion.

[15] The Lord-in-waiting Lord Wallace of Saltaire said on behalf of the government that it would be "inappropriate" to publish the report in the months leading up to the next general election in 2015.

[16] In August, it transpired that the Report would in any event be further delayed, possibly into 2016, due to the legal requirement of "Maxwellisation", allowing any person who is to be criticised a fair opportunity to comment on a draft prior to finalisation and publication.

[17] Chilcot wrote a letter to David Cameron in October 2015, announcing that the text could be complete by April 2016, and furthermore proposed a release date of June or July 2016.

Opening the proceedings, Sir John Chilcot announced that the inquiry was not seeking to apportion blame but that it would "get to the heart of what happened" and would not "shy away" from making criticism where it was justified.

On 29 October 2009, HM Government published a Protocol in agreement with the Iraq Inquiry on the treatment of sensitive written and electronic information.

[28] The inquiry heard mostly from civil servants, intelligence and security officials, diplomats and military officers from the first public hearings up until it recessed for Christmas.

[32] Special dispensations to attend were allocated to those whose close family were casualties of the war, some of whom shouted angry accusations at Blair during his second appearance.

[31] From the inquiry's resumption in January 2010, it heard predominantly from politicians and former government officials, including Alastair Campbell, Tony Blair's director of communications and on 2 February 2010, then-Secretary of State for International Development Clare Short, when she repeatedly criticised Blair, Attorney General Peter Goldsmith and others in the UK Government for what she maintained was deceiving her and other MPs in an attempt to obtain consent for the invasion of Iraq.

[5][39] Intervention might have become necessary later, but at the time of the invasion of Iraq in 2003, Saddam Hussein did not pose an immediate threat and the majority of the UN Security Council supported the continuation of UN weapons inspections and monitoring.

[51] The report found that Blair had attempted to persuade Bush of the need to seek support from the UN, European allies and Arab states, but that he "overestimated his ability to influence US decisions on Iraq".

Cameron said that he did not see "a huge amount of point" in "replaying all the arguments of the day" and said that focus should instead be on learning "the lessons of what happened and what needs to be put in place to make sure that mistakes cannot be made in future".

[54][55] After the report was issued, Jeremy Corbyn, the leader of the opposition and leader of the Labour Party - who had voted against military action - gave a speech in Westminster stating: "I now apologise sincerely on behalf of my party for the disastrous decision to go to war in Iraq in March 2003" which he called an "act of military aggression launched on a false pretext" something that has "long been regarded as illegal by the overwhelming weight of international opinion".

[62] The Financial Times reported, 'Every previous inquiry into Britain's decision to invade Iraq has swiftly been condemned by the public as a "whitewash".

[9] Conservative Party leader David Cameron dismissed the inquiry as "an establishment stitch-up", and the Liberal Democrats threatened a boycott.

In a diplomatic cable from the US embassy in London, released as part of Cablegate, Jon Day, director general for security policy at the British Ministry of Defence is cited having promised the US to have "put measures in place to protect your interests" regarding the inquiry.

"[75][76] In 2012, Attorney General Dominic Grieve was criticised when he vetoed the release of documents to the inquiry detailing minutes of Cabinet meetings in the days leading up to the invasion of Iraq in 2003.

Concurrently, the Foreign Office successfully appealed against a judge's ruling and blocked the disclosure of extracts of a conversation between Bush and Blair moments before the invasion.

[78] Speaking at a public meeting in 2013, David Owen said that the inquiry "is being prevented from revealing extracts that they believe relevant from exchanges between President Bush and Prime Minister Blair".

He blamed Blair and Cameron for this state of affairs, who he believed have entered into a private deal to prevent the publication of important documents out of mutual self-interest.

The UK media, "played on the 'hearts and minds' of the British public, constructing a moral case for the Iraq invasion that would convince the general population.