We do not know what form this public enquiry will take - I daresay that ministers themselves do not yet either. There are several possible forms... Here from :
https://www.publications.parliament.uk/pa/cm200405/cmselect/cmdfence/63/6312.htm
What is a Public Inquiry?
430. There are different forms a public inquiry might take. The House of Commons Library standard note on public inquiries states:
The term 'public inquiry' has a very broad meaning, and the history of the British government shows that there are in fact a number of forms of 'inquiry' available, designed, in principle to fulfil specific functions. Sometimes the wish may be simply to establish the relevant facts, leaving their interpretation, the allocation of 'blame' and recommendations for the future to other agencies such as Ministers, Parliament or the courts. In other circumstances it may be thought desirable that the 'inquiry' itself undertake these broader, perhaps more delicate tasks. A prime purpose of some inquiries may also be to allay public (and Parliamentary) disquiet about some public issue or a 'scandal'.[639]
431. The relevant Minister usually establishes the inquiry format, who heads it, its membership, its terms of reference and the form in which the report is made. An inquiry headed by a judge or senior lawyer is often called a 'judicial inquiry' although this is simply a descriptive term.
432. Currently the Tribunals of Inquiry (Evidence) Act 1921 allows a public inquiry to be established with all the powers of the High Court as regards the examination of witnesses, production of documents and summoning of witnesses. Such an inquiry may only be established following a resolution of both Parliament. In the more than eighty years since it came into force there have been just 25 inquiries set up under the 1921 Act, the two most recent being the Harold Shipman Tribunal of Inquiry set up in 2001 and the Bloody Sunday Tribunal of Inquiry set up in 1998.
433. An often-used alternative to formal public inquiries under the 1921 Act has been departmental inquiries set up by ministers. Such inquiries are usually advisory in nature and their exact remit is set out in terms of reference by the relevant minister. Recent examples include 'Lessons learnt from the Foot and Mouth Disease Outbreak Inquiry' (9 August 2001) and the Inquiry into the Soham Murders (June 2004). The Review by Nicholas Blake QC, which we consider later in this report, also fits the definition of a departmental inquiry.
434. Many departmental inquiries are classed as judicial inquiries because they are conducted by a judge. Although their procedures vary from case to case, in general they are investigative in character. They have no power to compel witnesses to attend but the lack of statutory power does not seem to be a major hindrance to their work. As Sir Michael Bichard, Chairman of the inquiry into the Soham murders said:
The Inquiry does not have statutory powers, but if I find that that hinders me in any way in my investigation or if I believe that an individual or organisation is not cooperating fully, then I will return to the Home Secretary and ask for such statutory powers, and he has made it clear to me that they will be made available.[640]
435. Examples of such judicial inquiries are the Scott Inquiry into Matrix Churchill (1992) and the Hutton Inquiry into the death of Dr David Kelly.
436. The current framework for inquiries will be revised by the Inquiries Bill, currently before Parliament. The Government's stated aim for the Bill is to provide a framework under which future inquiries can operate effectively and produce practicable recommendations in reasonable time and at a reasonable cost. The Bill repeals the 1921 Act and the statutory basis for inquiries and makes provision for Ministers to set the terms of reference of an inquiry and appoint the chairman and other members. It also gives the Minister power to enable the inquiry to summon witnesses, and to decide whether evidence is heard in public. The Minister may also decide the extent to which the report itself is made public.[641]