John Baron is a member of the Foreign Affairs Select Committee, and MP for Basildon and Billericay

That we went to war in Iraq on a false premise can be of little doubt – there were no weapons of mass destruction. But the question that has remained unanswered is whether the Number 10 of the time deliberately misled the nation as to the case for war.

It is a question that has haunted many Parliamentarians on both sides of the political divide since that fateful evening in March 2003: it has haunted the corridors of power; above all, it has haunted those who lost loved ones in this conflict. This is why the Chilcot inquiry is so important, and why we must allow Sir John time to finish its final leg – no previous inquiry has had its remit; no subsequent inquiry will be as authoritative.

The decision to invade Iraq ranks as Britain’s greatest foreign-policy disaster since the Suez Crisis of 1956. It was a grievous ‘forced error’ by the U.S and British Governments, predicated on a false premise, and has done untold damage to our international reputation, to say nothing of those who were killed or injured during the conflict.

It is therefore imperative that we get the bottom of why the Government decided to intervene in Iraq, and learn from the mistakes. This was one of the chief reasons behind the establishment of the Iraq Inquiry in 2009, headed by Sir John Chilcot, and why the eventual report is so keenly anticipated.

The report’s delay should be put into context. The Bloody Sunday Inquiry, established in 2000, for example, reported in 2010, having been expected to publish in 2007 or 2008. It was narrowly focused on the happenings of a single day in 1972. By contrast, given the wide remit of the Chilcot inquiry – essentially investigating all British involvement in Iraq between 2001 and 2009 and the thousands of people who played a role in these proceedings – it is not surprising that this has turned out to be a bigger job than anticipated.

But the remit of the Inquiry is not the only reason for the delay in publication. There seems little doubt that the length of time required to declassify some documents has played its part in delaying the report. Indeed, there is speculation that the Civil Service has not been forthcoming in clearing documents as quickly as it might, or is overly relying on a particularly pure reading of the rules surrounding disclosure. The ‘compromise’ regarding disclosure of conversations between Tony Blair and George Bush during the second half of 2002 hints at the intricacies involved.

Added to this problem is that some documents, once cleared for publication, raise legitimate fresh avenues of investigation. If we want a thorough and worthwhile report, it would seem unwise to prevent Chilcot and his team from following up these new leads when they deem it necessary. Likewise, it seems unjust to blame Sir John for delays outside his control. I am not sure that the mass resignation of the Inquiry panel in protest, as some have suggested, would be very productive.

Much attention has rightly been paid to the ‘Maxwellisation’ process, by which those due for criticism are given a right of reply. This seems reasonable: if an individual can demonstrate a factual error in the report it makes for a more robust and valuable account in the end. It would be the very worst outcome if, after publication, the report were torn to shreds by legal actions and counter-claim. Such a result would inevitably cast doubt over all the report’s conclusions.

Having met Sir John as part of his investigations about my Parliamentary questions and FOI requests (upheld by the Information Commissioner) uncovering the extensive role of spin-doctors in the Foreign Office’s Coalition Information Centre in the run-up to the war, and having questioned him when he appeared before the Foreign Affairs Select Committee earlier this year, I have no doubt he is determined to answer the central question of intent.  Sir John and his panel know that history is watching them, and that their reputations are on the line when historians of the future come to write their accounts.

My foreign policy decisions in the Commons have largely defined my political ‘career’. As an MP who resigned from the Shadow Front Bench to vote against the Iraq War, I feel it is especially important to learn the lessons of our involvement. Our subsequent interventions in Afghanistan post-2006, in Libya, and the government’s wish to intervene in Syria, suggests this has not yet happened. For these reasons, I hope the report will be published soon – but only when it is ready, and not in haste. We owe this to ourselves and particularly to the families affected.