It may come as no surprise that all is not well in the complicated land of the Chilcot Inquiry

Whatever else, Baroness Butler Sloss’s suggestion this week that Sir John Chilcot should have set a deadline on responses to the draft Iraq report, is another reminder that all is not well in inquiry land. And while it was probably not her intention, it will no doubt fuel the attempts by politicians to force the inquiry to publish its report before it feels ready. Of course it's hard to see why time limits shouldn’t be set on “Maxwellisation”, under which those facing criticism are allowed to respond ahead of a draft report’s publication. How far deadlines would hasten publication of the Chilcot report however is less clear.

For in an inquiry of this huge scope, and especially one in which some relevant documents were not put to the witnesses when they gave evidence because they were not yet available, Maxwellisation is an inevitably cumbersome process. Suppose witness A says “well actually you've got it all wrong, that wasn’t my fault; it was B’s.” Either the letters have to be sent out sequentially so that the one to B can take into account the claims by A, or B has to be written to a second time to take account of A’s new claim. That, broadly, was the problem encountered by Lord Justice Scott as different parts of government tried to wriggle their way out of the famous Arms to Iraq enquiry in 1992 – a process which dragged it out for two years.

Of course, the latest impatience over Maxwellisation is all the sharper because of the long delay before the draft sections even went out. But that was in large part because of a government resisting, for whatever reason, the release of documents. Nor is Chilcot alone. The regulators’ inquiry into the HBOS collapse, established after pressure from the Treasury Select Committee, was supposed to appear by the end of last year, and still hasn’t. The Banking Commission had already produced a report savaging what its – and the Select Committee’s – chairman Andrew Tyrie called the “catastrophic failures of management, governance and regulatory oversight” in the HBOS case. The Commission also flagged up detailed questions the Financial Conduct Authority and the Prudential Regulation Authority (PRA) needed to answer about those failures – including those of their predecessor, the Financial Services Authority. Those currently expected to be criticised in the report include Lord Stevenson, who was HBOS chairman.

Explaining the delay, last month the PRA’s Sir Andrew Bailey shed some incidental light on how Maxwellisation can work, especially when the rich or powerful, not to mention their lawyers, are concerned. Not only had it received 1,425 “representations” from 35 individuals, but it now had to “remaxwellise” those who, as a result of changes to the report, were facing increased criticism. The history of “Maxwellisation” is odd. After the 1971 Department of Trade and Industry (DTI) report which denounced Bob Maxwell as not “a person who can be relied on to exercise proper stewardship of a publicly quoted company”, Maxwell secured an interim high court judgement that the DTI inquiry had not been fair. And so it became public policy to ensure that anyone criticised in a future inquiry should be told in advance of its planned conclusions and given ample time to dispute them.

You can see why this judgement would have put the wind up Whitehall. Except that when the case went to trial a second High Court judge overturned the first ruling, and was then handsomely vindicated by the Court of Appeal under the chairmanship of Lord Denning, no less. Indeed, Denning ruled that the DTI inspectors had acted with “conspicuous fairness” and “had put to the plaintiff all the matters which appeared to call for an answer,” adding for good measure that that it was “not necessary for the inspectors to put their tentative conclusions to the witnesses in order to give them an opportunity to refute them and ... the inspectors had not given any undertaking to do so.”

So, while everyone agrees that those criticised in an inquiry have a right to natural justice in its conduct, the Maxwell case did not establish a legal basis for the assumption that “Maxwellisation” is the way it has to be done. And that isn’t how it’s done in statutory public inquiries set up under the 2005 Act. Instead such inquiries ensure that natural justice prevails as they go along. Before witnesses appear, they are sent a “Salmon letter” outlining any allegations that have been made against them, and of course they can be recalled if discrepancies emerge during the subsequent course of the inquiry.

Chilcot, set up by Gordon Brown, is not such a statutory inquiry – again not Sir John’s fault. Indeed governments are unwilling to set up such inquiries into themselves. But it might have been better if Chilcot had been able to follow the 2005 model more closely. Maybe it was politically impossible to delay its hearings until it had dragged the bulk of the documents – the sheer scale of which it probably did not then realise – from the government. But ideally it would have recalled the witnesses when it did have them, rather than rely on the long process of Maxwellisation.

The proof will be when the report is published. But there is no evidence that the inquiry team are being other than conscientious in getting to the truth about Iraq. That said, the long delays may well mean that future governments will come under more pressure to set up statutory 2005 Act inquiries into their own conduct.

In the meantime, with some foresight the Treasury Select Committee sent in two top former building society executives to monitor the regulators’ HBOS enquiry. They should at least be able to report on whether Maxwellisation was abused by respondents and whether it can be streamlined.