Règle correspondante
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 141. Legal Advisers for Armed Forces
The UK LOAC Manual (2004) states:
Legal advisers are required to be available, when necessary, to advise military commanders at the appropriate level on the application of the law of armed conflict and also on the appropriate instruction to be given to members of the armed forces in this subject. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 16.5.
In 2008, the UK Army published the Aitken Report which investigated cases where members of the British Army were alleged or proven to have mistreated or killed Iraqi civilians outside the context of immediate combat operations in 2003 or early 2004. The report stated: “Legal advice is available for commanding officers and higher authorities to assist with decisions on referring appropriate cases to the APA [Army Prosecuting Authority].” 
United Kingdom, Army, The Aitken Report: An Investigation into Cases of Deliberate Abuse and Unlawful Killing in Iraq in 2003 and 2004, 25 January 2008, § 28.
The report further stated:
To improve the quality of legal advice in training, and to capture lessons learned on operations, an Operational Law Branch was fully established in January 2006 under an operationally-experienced Army Legal Services Brigadier. It provides expert advice on the practical application of international law on operations, and reviews all material taught in both the adaptive foundation and on pre-deployment training. No Army lawyer deploys on operations without having attended the requisite training in operational law, delivered through a combination of internal military instruction and external academic sources. Army lawyers are now embedded at the Defence Intelligence and Security Centre to provide immediate advice on the training delivered there. APA prosecutors deploy to operational theatres to support the Service Police directly. In addition, a joint legal cell has been established at the Development, Concepts and Doctrine Centre to provide legal advice on doctrine. 
United Kingdom, Army, The Aitken Report: An Investigation into Cases of Deliberate Abuse and Unlawful Killing in Iraq in 2003 and 2004, 25 January 2008, § 31.
In 2009, in response to a question in the House of Commons, the UK Secretary of State for Defence wrote: “Trained and qualified lawyers are deployed on all standing operations and are an integral part of the targeting process, are consulted on all forms of the conduct of operations and are available for specialist queries if doubt exists.” 
United Kingdom, House of Commons, Written Statement by the Secretary of State for Defence, Hansard, 2 December 2009, Vol. 501, Written Statements, col. 727W.
In 2010, in its closing submissions to the public inquiry into the circumstances surrounding the death of Baha Mousa and the treatment of those detained with him by UK armed forces in Iraq in 2003, the UK Ministry of Defence stated regarding Article 82 of the 1977 Additional Protocol I:
11.7 There is an extensive ICRC commentary which accompanies this provision. It makes clear that the requirement to make legal advisers available arose from the increasingly complex, detailed and extensive nature of IHL. The conditions for the use of legal advisers and the choice of methods of training them are left to the discretion of the Contracting Parties. It is plain from the commentary that what is envisaged is the provision of either qualified lawyers or military officers who have trained in the requirements of IHL.
11.8 It is also clear from the commentary that flexibility on the use of legal advisers is left to the discretion of the Parties so as to avoid questioning the validity of orders from a superior whenever a legal adviser has not been consulted, and even to avoid “putting into question the whole military hierarchy”, and to prevent the incorporation of legal advisers from weakening the sense of responsibility of commanders.
11.9 As the inquiry has heard, the MOD’s legal advisers are qualified solicitors or barristers. Some are members of the Army Legal Service (ALS) and therefore enjoy the benefits not only of professional legal qualifications but also a high level of military knowledge. At the highest levels of command in the army it is recognised in the ICRC commentary that the presence of renowned experts may be necessary in some circumstances, but this solution cannot necessarily be adopted at all levels where the presence of legal advisers is necessary for two reasons. Firstly, there are not enough of such legal advisers even to service the British armed forces, still less those of the more than a hundred other States Parties to [the 1977] Additional Protocol I and secondly in operational theatre a much broader set of skills are required in order to carry out this role effectively. Operational law is much wider than the treaty obligations contained in the [1949] Geneva Conventions or Additional Protocols. When deployed on operation all ALS officers need to be able to provide advice across a broad spectrum of domestic, military and international law. In order for them to provide this advice they must have the necessary military skills to be able to deploy with confidence into hostile environments such as Iraq or Afghanistan. When so deployed they will routinely be subjected to indirect fire from the enemy and may very well have to use a personal weapon in the defence of themselves or others. They will also be subjected to extreme temperatures while carrying out their duties.
11.10 Others are lawyers form the Government Legal Service (GLS) who are deployed to particular posts within PJHQ [Permanent Joint Headquarters] and MODLA because they have shown that they have the requisite skills and judgment necessary for the post in question. During their careers GLS lawyers gain a wide range of public law experience including in core areas such as human rights and the interpretation of domestic and international legal frameworks. GLS lawyers are placed in particular posts where they have shown that they have the requisite skills and judgment necessary and, where they don’t already have relevant specialist experience, the aptitude to understand and apply new areas of the law quickly and competently. GLS lawyers are not sole practitioners. They have access to specialist training and know-how and draw on the expertise of their colleagues (both civilians and military). They routinely liaise with lawyers across different departments and agencies and do, for example, draw on the international law expertise in the Foreign Office. They are experienced in advising on wider propriety issues and the need to advise Ministers of particular difficult legal issues and seek the advice of the Attorney General as appropriate.
11.12 The inquiry has heard evidence that legal advisers were deployed from the very top strategic level through the operational level and down to the tactical level of a (non independent) brigade … Accordingly, the depth to which legal advisers were in fact deployed exceeded that envisaged by the ICRC. 
United Kingdom, Ministry of Defence, Closing Submissions to the Baha Mousa Public Inquiry on Modules 1–3, 25 June 2010, §§ 11.7–11.10 and 11.12, pp. 24–27.
[footnotes in original omitted]