The latest delay in the publication of the Chilcot inquiry into the Iraq war report points to the corruption and decay of parliamentary rule in the UK.

The inquiry into an illegal war, justified by what was known at the time to be a pack of lies about Iraq’s possession of “weapons of mass destruction,” has only proved that war crimes that led to the destruction of an entire country do not warrant even the token censure of its chief architects.

The official inquiry into the 2003 Iraq war, chaired by Sir John Chilcot, will now not publish its report before the May 7 General Election.

The inquiry was reluctantly convened by then Labour leader Gordon Brown in 2009. Its last public hearing was in 2011. The four years since then have been dominated by conflicts over whether crucial documents regarding a personal exchange of messages between former US President George W Bush and then Prime Minister Tony Blair in the run-up to the war could or could not be published. Now we are told that, prior to May 7, it is not possible to evaluate the responses from leading figures criticised in the report.

Chilcot’s latest excuse, made in a letter to Conservative Prime Minister David Cameron, also makes reference to the fact that he had made “substantial progress” in negotiations with Cabinet Secretary Sir Jeremy Heywood, that will mean that 29 of Blair’s notes to US President George W. Bush can be published as part of the report, “subject to a small number of essential redactions.”

There is no mention of what will happen to the 130 records of conversations between the two.

The letter prompted Blair’s spokesperson to insist: “We have repeatedly said that it is not true to say that Tony Blair has caused the delay in the report’s publication. … Sir John’s letter makes reference to notes and records concerning Mr Blair, which some may interpret as an implicit suggestion that Mr. Blair caused the delay, this is not true. On the contrary, he regrets this delay in its publication. Incorrect allegations and politically motivated speculation do nothing to shine a light on the issues involved. It is an independent inquiry and it should be allowed to proceed with its work.”

This is somewhat disingenuous. Blair need not move a muscle to delay Chilcot. Not only is he ably protected by the civil service and his own people, but the United States has made clear that it would reconsider security collaboration with Britain if any politically embarrassing private exchanges between Bush and Blair were published.

The publication of even a partial and redacted documentary record is only happening because the deliberately toothless inquiry was becoming a standing joke due to its grovelling before the guilty.

When setting it up, Brown, who succeeded Blair in 2007, ensured that no one would be held accountable for any actions. Chilcot’s terms of reference were that no one could be subjected to any prosecutions or legal proceedings as a result of findings that would focus on the “lessons that can be learned” from British involvement in the Iraq war.

To this end, in 2011 Chilcot offered to redact anything from the Bush-Blair documents the government thought should not be included and reassured Heywood on May 28: “Accordingly, the requests submitted by the Inquiry last summer were for permission to disclose quotes or gists of the content. We have concluded they are sufficient to explain our conclusions. … We have also agreed that the use of direct quotation from the documents should be the minimum necessary to enable the Inquiry to articulate its conclusions.”

According to Philippe Sands QC, international law professor at University College London speaking to the Guardian, among the records that will not be published is a minute of a meeting between Blair and Bush at the White House on January 31, 2003, six weeks before the invasion. “According to well-placed sources, Blair then told Bush he ‘would support the use of force without a second UN security council resolution’,” the Guardian notes.

It is in the same spirit of deference that Chilcot explained in his letter that individuals who were going to be criticised in the report were “currently being given the opportunity to respond to provisional criticism”—in their own good time, of course. Chilcot has sent “Salmon letters”—named after Lord Salmon, who held an inquiry into public ethics in the 1970s—to the relevant figures. Though unspecified, the common assumption is that it is their objections that have led to the latest delay.

It was only last summer that Chilcot finally drafted the passages containing criticism of these figures—said to include former Foreign Secretary Jack Straw, then MI6 head Sir Richard Dearlove, former Attorney General Lord Goldsmith and then Defence Secretary Geoff Hoon.

Heywood, the cabinet secretary, will be questioned next week by the Public Administration Select Committee (PAC).

Cameron and his coalition partner, Liberal Democrat leader Nick Clegg, have both sought to make political capital at Labour’s expense over the latest turn in the ongoing scandal.

Cameron has backed a call for Chilcot to appear before MPs in the Foreign Affairs Select Committee to explain the reason for the latest delay in the next two weeks. Sir Richard Ottaway, Tory chairman of the committee, said, “There must be a way of devising an inquiry that doesn’t take more than five years to complete.”

Sir Peter Tapsell, the Tory Father of the House of Commons, spoke in parliament of the “widely held suspicions that Mr. Blair conspired with President George W. Bush several months before March 2003 and then systematically sought to falsify the evidence on which that action was taken.”

Former Conservative foreign secretary, Lord Douglas Hurd, has described the way the inquiry has dragged on and has gone beyond questions of mere negligence and forgivable delay. “It is becoming a scandal,” he told peers in the House of Lords.

Cameron has also noted that Labour leader Ed Miliband had opposed the convening of an inquiry in 2006. This is especially damaging to Miliband as he has made great play of having opposed the Iraq war before he became an MP in 2005 and has been used by Labour as a vehicle to distance itself from the crimes of the Blair era.

Clegg, the deputy prime minister, stated, “The public have waited long enough and will find it incomprehensible that the report is not being published more rapidly than the open-ended timetable you have now set out. …

“If the findings are not published with a sense of immediacy, there is a real danger the public will assume the report is being ‘sexed down’ by individuals rebutting criticisms put to them by the inquiry, whether that is the case or not.”

Every word of criticism of both Labour and the Chilcot inquiry is, of course, true. But they come from the mouths of those who are themselves guilty.

Cameron fully supported the Iraq war, as did his party. Clegg did not become an MP until 2005, and his party made an initial show of opposing the war before falling into line once it began. But his posturing is hypocritical. His last foray as an opponent of the Iraq war came during Prime Minister’s Question Time back in 2010, when he described it as illegal. Immediately afterwards, he described this view as a “personal one,” rather than the position of the governing coalition in which he sits. He plays the same Pontius Pilate role today, even as Britain has renewed military operations in Iraq against Islamic State and threatens war against Syria.