The power to do what exactly? MI6’s functional vires – UK Constitutional Law Association

On 31 July, the final day of Trinity term, and so of the legal year, there was published by the Investigatory Powers Tribunal an OPEN judgment in a case entitled A Complainant v The Secret Intelligence Service (‘the MI6 case’). In recent years the IPT has become a much more visible contributor to the legal landscape, and its judgments are often the best source of information about the law applicable to the work of the security and intelligence agencies (‘SIAs’), and to other bodies enjoying access to powers of surveillance etc. This judgment, however, was notably laconic. It informed the reader that the Tribunal had ruled on ‘an issue of law’ regarding the powers conferred on the Secret Intelligence Service (‘MI6’) by section 1(1) of the Intelligence Services Act 1994 (the short statute which first gave MI6 a statutory basis and which governs it to this day). It had ruled, the judgment stated in its sole substantive paragraph, that the provision in question ‘conferred on SIS the vires to engage in the tasks necessary to fulfil the functions specified in the subsection (1)(a) and (b)… irrespective of whether those tasks took place in the United Kingdom or overseas.’ This post considers some of the background to, and possible implications of, this recognition of what we might label MI6’s ‘functional vires’.

Background

A first point worthy of note is that the IPT’s judgment in the MI6 case refers to a ‘complainant’ rather than a ‘claimant’. The Tribunal’s jurisdiction has a number of aspects but a key distinction within its rather eclectic body of case law is that between matters which come to it under s 65(2)(a) of the Regulation of Investigatory Powers Act 2000 and those which come to it under s 65(2)(b). The former are Human Rights Act proceedings which must be brought in the Tribunal rather than the High Court because they are, for example, brought against one of the SIAs – not only MI6, but also MI5 and GCHQ. In such cases the party bringing the case is the ‘claimant’. Under s 65(2)(b), however, the IPT has a broader jurisdiction over ‘complaints’ relating to various sorts of conduct which a person believes to have been carried out in relation to him or his communications and to have either been carried out by an intelligence service or been carried out in what the statute describes as ‘challengeable circumstances’. One implication of this distinction is that a complaint can be made to the Tribunal under 65(2)(b) even where the individual in question is not alleging a breach of his or her Convention rights. 

So, for example, in Al-Nashiri – relating to a Saudi Arabian citizen subjected to torture and inhuman and degrading treatment as part of a CIA programme, and alleging British complicity therein – the IPT held that the claimant was not at the material times within the UK’s jurisdiction for the purposes of Article 1 of the ECHR and so could not make a claim to the IPT under s 65(2)(a), but later permitted him to amend his pleading so as to include a complaint under s 65(2)(b). Under this jurisdiction, the 2000 Act provides that the Tribunal is to investigate the matter and then determine the complaint, applying ‘the same principles as would be applied by a court on an application for judicial review’. In Al-Hawsawi, on similar facts to Al-Nashiri, the IPT held that its complaints jurisdiction did not encompass common law causes of action, but that it had jurisdiction to consider an amended complaint from which various claims in tort had been deleted. The amended complaint, it said, was now ‘tolerably clear’:

[I]n essence, it alleges that the Respondents behaved in a way that they had no power to behave, that is to be complicit in the Complainant’s torture or other similar ill-treatment. If one formulates the question in public law terms (“did the Respondents have power to behave in that way?”), the answer would clearly be “No”.

The Tribunal also extended the usual one-year time limit to permit the bringing of the complaint, in part on the basis that ‘the underlying issues raised by this complaint are of the gravest possible kind’. These two cases were argued before the Tribunal in June of this year – what, if any, is their relationship with the OPEN judgment in the MI6 case issued at the end of the following month is not clear.

Geography

The formulation of the key sentence in the recent MI6 case – ‘The Tribunal ruled that s.1(1) conferred on SIS the vires to engage in the tasks necessary to fulfil the functions specified in the subsection (1)(a) and (b)… irrespective of whether those tasks took place in the United Kingdom or overseas’ – works to draw attention in the first place to the issue of geography. MI6 can exercise the relevant powers both inside and outside of the United Kingdom. Why this point might be disputed must therefore be considered briefly. MI6 is the UK’s foreign intelligence agency. It was continued in existence (having previously existed without express parliamentary authorisation) by the Intelligence Services Act 1994, which identified two functions for it – ‘to obtain and provide information relating to the actions or intentions of persons outside the British Islands’ (emphasis added) and ‘to perform other tasks relating to the actions or intentions of such persons’. These functions are exercisable only on one of three grounds, being a variation on the standard trifecta of grounds which exist in this area (national security, economic well-being, and preventing and detecting serious crime). Though an institution of the British state, therefore, MI6’s mission is resolutely foreign-focused, and it may have been argued that its legal authority to act inside the United Kingdom was in some sense limited by that focus; that the power to act within the United Kingdom was, perhaps, restricted to its counterpart the Security Service (‘MI5’). If such an argument was made, the Tribunal has, it would seem, rejected it. 

Alternatively, the argument may have been made that MI6’s ability to act outside of the United Kingdom was limited by some combination of the international legal rules applicable to the work that it carries out and the absence of anything in the 1994 Act capable of overcoming the presumption that Acts of Parliament are not intended to have extra-territorial effect. One aspect of any such argument, if it took place, may have been the most famous of the provisions of the 1994 Act: that found in section 7, which permits the Secretary of State, under strict conditions, to grant authorisations negating any criminal or civil liability which would otherwise arise within the United Kingdom for acts done outside of the ‘British Islands’. One use to which this power has historically been put, we know, is where MI6 has taken steps which may result in it becoming complicit with mistreatment by foreign partners. Such a course of events is now governed by a document known as ‘The Principles relating to the detention and interviewing of detainees overseas and the passing and receipt of intelligence relating to detainees’, being the successor of a document put in place largely as a result of the sorts of allegations of UK involvement in US extraordinary rendition and mistreatment that are once again at issue in the Al-Nashiri and Al-Hawsawi cases. The existence of this power might be taken to indicate a clear intention that MI6 be able to act outside the United Kingdom in the first place, engaging in activities in respect of which – absent such an authorisation – relevant liability would arise. Again, if the argument was made that the MI6 had no, or somehow more limited, vires to act outside the United Kingdom the IPT appears to have rejected it: the vires it recognises in its ruling exist irrespective of whether the acts in question take place inside or outside the UK.

Vires

Though the structure of the key sentence in the OPEN judgment works to draw attention in the first place to this conclusion as to geography, that conclusion is in fact predicated upon a potentially much more significant conclusion as to vires. That is, the OPEN judgment involves the holding that section 1(1) of the 1994 Act is a source of power for MI6, conferring on it ‘the vires to engage in the tasks necessary to fulfil the functions specified in the subsection’. Though this is in keeping with the logic of previous judgments not only of the Tribunal but also of the Court of Appeal, the implications of that logic as applied here seem much further reaching than are those of prior judgments. 

Some background as to how the courts have addressed analogous provisions is required. In the ‘Third Direction’case, it was argued that MI5 did not possess the necessary vires to authorise its agents (third-party informants rather than employees of the Service) to participate in criminal activity. A split IPT held that MI5 did in fact possess the requisite authority, which it found in section 1(2) of the Security Service Act 1989 – the equivalent of the provision at issue in the MI6 case. This was not an explicit power, the majority accepted, but an ‘implied’ one ([60]). In dissent, Professor Graham Zellick suggested that the conclusion of the majority rested upon a misreading of the relevant provision as one which conferred powers, which was not in fact the case:

Section 1 is not on its face a provision conferring powers at all. It sets out functions or purposes. It might be called an objects clause. In other words, it defines the limits or scope of the Service’s activities. In classic public law terms, it is stating that lawful action may be carried out by MI5 for these purposes but only for these purposes. Action, even if on its face lawful, which is carried out for any other purpose will be ultra vires and therefore unlawful. So far from conferring specific or additional powers on the Security Service, section 1(2) is in law a limiting provision.

The decision of the IPT was upheld by a unanimous Court of Appeal, which put emphasis on the fact that – so far as it was concerned – MI5 possessed the power to ‘run’ agents who participated in criminality prior to the enactment of the 1989 Act (under, it would seem, the prerogative) and that the 1989 Act in effect continued that position in place. The Supreme Court refused permission to appeal because, it said, the application for permission did not raise an arguable point of law, with the immediate implications of the litigation being muted by the enactment of the Covert Human Intelligence Sources (Criminal Conduct) Act 2021. The President of the Investigatory Powers Tribunal, Lord Justice Singh, was in the majority in its judgment in the Third Direction case, and was part of the panel which later gave the judgment in the MI6 case: that latter judgment, terse though it is, was no doubt influenced very strongly by the Court of Appeal’s endorsement of the earlier decision. 

The basic logic appears identical. The Security Service Act 1989 identifies functions for MI5 and in doing so, the courts have held, affords it certain vires; similarly, the Intelligence Service Act 1994 identifies functions for MI6 (and, we might note, the Government Communications Headquarters) and in doing so affords it vires. The context of these judgments, however, would seem to make the latter potentially more consequential. In the Third Direction case a specific activity was at issue, and the ratio of that judgment – a long and detailed OPEN judgment, we might note – is that MI5 possessed the requisite vires to undertake that activity. In the MI6 case – as already observed, strikingly laconic – we do not know what specific activity or activities was at issue, and the ratio of the judgment is not that MI6 enjoys the vires to undertake particular activities, but that MI6 possesses the vires to ‘to engage in the tasks’ – what tasks? – ‘necessary to fulfil’ its statutory functions. Those functions – ‘to obtain and provide information relating to the actions or intentions of persons outside the British Islands’ and ‘to perform other tasks relating to the actions or intentions of such persons’ – are by no means tightly drawn. Though limited by the purposes identified in s 1(2) of the 1994 Act, the category of tasks which MI6 might engage in under the logic of this judgment would seem to be potentially very broad indeed, notwithstanding that at first (and perhaps even second) glance the provision in question does not seek to afford it any power to act at all.

The breadth of this conclusion, and the desire to understand its practical implications, raise what we might call the Entick v Carrington question: when and why do public authorities require legal authority for their actions? Though a more-ambitious reading of that judgment is sometimes offered, the basic rule which emerges from Entick is that public bodies requires legal authority in order to interfere with an interest which is protected by (public or private) law. One problem with the Third Direction case is that it was not, in general terms, clear that MI5 in fact required legal authority for what it was doing, which was in effect (it claimed) making representations to the prosecuting authorities as to where the public interest lay in the event that a decision was being taken whether to prosecute one of its agents for a criminal offence his or her involvement in which MI5 had authorised. Either way, it was accepted by all concerned that the MI5 guidelines at issue did not – could not – involve the grant of criminal immunity, for which (much) more explicit statutory language would have been required. Considerable emphasis was placed on this point: the majority in the IPT case said that the judgments of the minority failed ‘sufficiently to draw the distinction between a power (or legal ability to do something) and an immunity from legal liability’; the Court of Appeal endorsed ‘the conclusion of the majority of the Tribunal; and in particular… their emphasis on the important differentiation between a power and an immunity.’ The broad vires recognised in the MI6 case must – on this logic – similarly create a ‘power’ rather than an ‘immunity’ and indeed there must be a suspicion that it is in many circumstances a power to do things for which no legal authority is in fact required. Defining vires by reference to functions necessarily casts a wide net – perhaps implausibly so.

The human rights context may be where the decision in the MI6 case is most significant. That is, the unusual recourse to the work of Wesley Newcomb Hohfeld on the distinction between a power and immunity by both the IPT and the Court of Appeal in the Third Direction case might be thought to have served two purposes. One was to distinguish the power being asserted (to authorise agents’ participation in criminality), which was not the subject of explicit statutory language, from the power to interfere with property (which was included, very explicitly indeed, in the 1989 Act, and is now available, in expanded form, to all three of the SIAs). The other was to bolster the conclusion that any interference with Convention rights caused by the authorisations in question was ‘in accordance with law’ for the purpose of the ECHR. This might seem to be less significant in the MI6 case: as a result of its statutory functions, and as Al-Nashiriri shows, it will usually be the case that those with whom MI6 concerns itself are outside the UK’s jurisdiction for ECHR purposes, and so there will be no risk of interference with Convention rights (and so, in the case of the qualified rights, no need to show that the conditions for a justified interference are met). 

But the common law also recognises a series of fundamental constitutional rights – including, quite possibly, a prohibition on torture – which can be interfered with by public authorities only where Parliament has authorised the interference in suitably clear statutory language. This point – on the so-called ‘principle of legality’ – was dealt with in a not entirely convincing manner by the Court of Appeal in the Third Direction case. Amongst other things, that court noted that even though Counsel for the appellant had ‘postulated some potential extreme instances’, it was ‘very difficult to see how “fundamental rights” will necessarily be “overridden” if the 1989 Act is to be interpreted as permitting the continuation of the “authorisation” of undercover agents to participate in criminality in the sense which we have explained, namely without granting immunity from criminal or civil sanction.’ MI5 enjoying merely a power and not an immunity, that is, the legal consequences of the acts so authorised would remain the same notwithstanding the authorisation. And so the inability of the provision at issue to satisfy the principle of legality was of no import. The same must then be true in the MI6 case – recognising to MI6 the vires which that judgment does will not permit any interference with fundamental rights recognised by common law, for section 1(1) of the 1994 Act creates a power rather than an immunity. And yet it seems inevitable that certain of the things that MI6 might want to do in pursuit of its functions – and so in purported exercise of the vires the IPT has recognised – will involve an interference with common law rights, where they apply. And so one consequence of the MI6 judgment may be to prompt a consideration of the extent to which fundamental common law rights are enjoyed by those outside the United Kingdom. If they do, these ‘functional vires’ are subject to an important, though uncertain, limit, of a sort not applicable to the genuine immunity created by section 7 of the 1994 Act.

Conclusion

Though the Intelligence Services Act 1994 contains only a few explicit powers, MI6 can avail itself of many other, highly intrusive, legal capabilities, now found mostly in the Investigatory Powers Act 2016. The decision of the IPT in the MI6 case effectively recognises a much broader, more diffuse, vires for that body, defined by reference not to specific acts, but to their necessity to fulfilling the functions identified for it in s 1(1) of the 1994 Act. This recognition seems to follow fairly directly from the decision of the Court of Appeal in the Third Direction case, but is more significant because of its abstract framing: we can only speculate as to how it might translate into concrete activities which MI6 might wish to undertake and for which it requires legal authority. Questions which the judgment prompts include those about the ability of these ‘functional vires’ to ground interferences with the Convention rights (where they apply), and their ability – which must be strongly doubted – to ground interferences with those fundamental rights recognised by the common law.

Paul Scott teaches at the University of Glasgow. Thanks go to Bernard Keenan and Daniella Lock for their comments.

(Suggested citation: P.F. Scott, ‘The power to do what exactly? The functional vires of MI6’, U.K. Const. L. Blog (9th September 2025) (available at https://ukconstitutionallaw.org/))