The reviewability of Acts of the Scottish Parliament (ASPs) at common law has, understandably, attracted considerable interest of late, on this blog and elsewhere.  However, the Supreme Court’s decision in AXA General Insurance Ltd v the Scottish Ministers [2011] UKSC 46 confirmed that the primary means of challenging ASPs is upon the grounds laid down in section 29 of the Scotland Act 1998, and there have in fact been several recent cases brought on statutory grounds which merit similar attention.

In comparative terms, the model of constitutional review – if it is appropriately so described – contained in the Scotland Act is a particularly strong one, permitting both pre- and post-enactment challenges; direct and collateral challenges; and inter-institutional and individual challenges.  Yet, as has frequently been observed, the courts have so far played a relatively limited role in policing the boundaries of the Scottish Parliament’s legislative competence.  Indeed, for the first decade after devolution, although there were a few cases, no legislation was found to be ultra vires, there were no inter-institutional challenges, and it was not until 2008 that any statutory ground other than breach of Convention rights was invoked (Logan v Harrower 2010 JC 1).

In the last few years, however, all this has started to change.  To begin with, the initial trickle of cases appears to be growing into a steady stream.  Whereas between 1999 and 2009 there were only nine reported cases in which legislative competence was in issue, since 2010, there have already been eleven such cases.

Secondly, in February and March of this year, the Scottish courts issued their first rulings that provisions were ‘not law’ in terms of section 29 of the Scotland Act.  Cameron v Cottam 2012 SLT 173 concerned section 58 of the Criminal Justice and Licensing (Scotland) Act 2010, which imposed a standard bail condition requiring the accused to participate in identification procedures and to allow prints, impressions or other bodily samples to be taken.  Because the condition was mandatory and therefore not necessarily justified in particular cases, the Court of Criminal Appeal held that it breached Article 5 of the European Convention on Human Rights (ECHR).  In Salvesen v Riddell [2012] CSIH 26, the Inner House of the Court of Session held that section 72 of the Agricultural Holdings (Scotland) Act 2003 was an unjustifiable interference with Article 1 Protocol 1 ECHR.  The 2003 Act abolished a form of agricultural tenancy – the limited partnership tenancy – which was used to prevent tenants gaining security of tenure, and replaced it with a statutory form of limited duration tenancy which gives tenants enhanced rights.  Following a wave of termination notices issued by landlords in anticipation of the legislation being passed, an anti-avoidance measure was inserted into the Bill which retrospectively cancelled the effect of such notices.  Giving judgment for the court, Lord Gill held that the provision went further than was justifiable for anti-avoidance purposes and was in fact punitive, motivated by the sponsoring minister’s view that the landlords’ action was immoral.  On the contrary, according to Lord Gill, there was nothing immoral in landlords exercising contractual rights to which tenants had agreed.

The third notable change is in the character of recent cases.  Although Convention rights remain the most popular ground of challenge, cases are at last emerging on other section 29 grounds.  The first to involve the devolved/reserved competence boundary was Logan v Harrower, which challenged the validity of section 45 of the Criminal Proceedings Reform etc (Scotland) Act 2007, which raised the maximum sentence available upon summary conviction in the Sheriff Court, insofar as it applied to road traffic offences, which are reserved under Schedule 5, Head E1 of the Scotland Act.  Although the challenge failed in the appeal court, it was essentially revived before the Supreme Court in Martin v HM Advocate 2010 SC (UKSC) 40.  The point at issue in both cases was a rather esoteric one, namely whether a general change to the criminal law, carried out for a devolved purpose, but which for reasons of consistency made changes to the law on reserved matters, and would therefore have been intra vires in terms of section 29(4), was nevertheless ultra vires because it altered a rule which was ‘special to a reserved matter’ in terms of Schedule 4 paragraph 2(3).  By a three/two majority, the Supreme Court in Martin held that the rule was not ‘special to a reserved matter’ because it merely altered the procedural route by which a particular sentence could be imposed, rather than the maximum sentence available for road traffic offences.  However, six months later, in Henderson v HM Advocate 2011 JC 96, the Crown had little option but to concede that a similar general sentencing provision – a power to impose an order for lifelong restriction created by section 1 of the Criminal Justice (Scotland) Act 2003 – should be read down so as not to apply to offences under the Firearms Act 1968.  Firearms is also a reserved matter (see Schedule 5 Head B4), and the effect of the impugned legislation clearly was to increase the maximum sentence available in such cases.

Another ASP which has had multiple challenges is the Tobacco and Primary Medical Services (Scotland) Act 2010, which, inter alia, bans displays of tobacco and smoking-related products (section 1) and cigarette vending machines (section 9).  In Sinclair Collis v Lord Advocate 2011 SLT 620, it was claimed that the section 9 ban breached both Article 1 Protocol 1 ECHR and Article 34 of the Treaty on the Functioning of the European Union (TFEU) (free movement of goods).  The Lord Ordinary rejected both challenges, holding that although it was not clear whether the vending machine ban fell within Article 34, it was in any case clearly a justified and proportionate restriction given its aim to protect public health, and that the same applied to the property rights challenge.  The attack was renewed in Imperial Tobacco v the Lord Advocate [2012] CSIH 9, this time on both provisions and on the grounds that they related to consumer protection, which is a reserved matter under Schedule 5, Heads C7 and C8, and modified section 6 of the Union with Scotland Act 1706, so far as it relates to freedom of trade, reserved by Schedule 4 paragraph 1(2)(a).  Imperial Tobacco is undoubtedly the most significant of the recent cases, since it is the first to involve a straightforward claim that an ASP has encroached upon reserved matters, and the Inner House’s decision contains important guidance on how such disputes are to be resolved.  In particular, the judges rejected the Lord Advocate’s argument, based on Robinson v Secretary of State for Northern Ireland [2002] UKHL 32, that, as a constitutional measure, the Scotland Act ought to be given a ‘generous and purposive interpretation’.  Although of constitutional significance, they insisted that the Scotland Act was not a constitution, but rather an Act of Parliament, and should therefore be interpreted in the same way as other statutes.  While statutes have to be interpreted in the light of their purpose, this requires specific evidence as to the background purpose, and in this case, since the purpose of Schedule 5 was simply to effect a division of powers between the Scottish and UK Parliaments, a purposive interpretation did not assist in determining where the dividing line was to be drawn.  Nevertheless, the court concluded that the tobacco bans were within competence: they were not consumer protection measures, and did not affect freedom of trade within the meaning of the Act of Union.

As to future challenges, litigation is widely anticipated in relation to the Alcohol (Minimum Pricing) (Scotland) Bill, again based on the claim that it is a disproportionate restriction on free movement of goods under Article 34 TFEU.  And the prospect remains of a challenge to the competence of the promised independence referendum, unless agreement is reached on an Order under section 30 of the Scotland Act to confer express power on the Scottish Parliament to legislate on this matter.  The independence referendum issue is, of course, also significant as the first instance of an open dispute between the Scottish and UK governments about the vires of proposed legislation.

Much more could be said about the decisions in these recent cases.  One might speculate, for example, as to the factors which led the courts to strike down the provisions in Cameron v Cottam and Salvesen v Riddell, without much show of deference in either case.  One could also explore the apparent differences in approaches to the interpretation of devolution statutes as between the majority and minority in Martin, or between the House of Lords in Robinson and the Inner House in Imperial Tobacco.  However, since both Salvesen v Riddell and Imperial Tobacco have been appealed to the Supreme Court, which is also due to give judgment in another case (ANS v ML) involving the compatibility of section 31(3)(d) of the Adoption and Children (Scotland) Act 2007  with Article 8 ECHR, further discussion might reasonably be postponed until these cases have been finally resolved.

There is, though, another question on which it is equally interesting to speculate: why is it that so many more, and more varied, challenges to the validity of ASPs have been raised in the last few years?  It has been suggested that the main reason for the previous relative lack of resort to the courts is because of robust internal policing of the boundaries of the Scottish Parliament’s legislative competence, both within the devolved institutions, and through inter-governmental negotiation, the latter assisted by political consensus between the Scottish and UK governments for most of the period since devolution.  There is undoubtedly some truth in this view, since there are strong supports within the Scotland Act for political resolution of vires concerns.  These include provisions for pre-legislative declarations by sponsoring ministers and the Presiding Officer that Bills are within competence (section 31), for pre-enactment references by UK and Scottish law officers to the Supreme Court (section 33), and, in some circumstances, for pre-enactment veto by UK ministers (section 35).  Provisions such as sections 30 and 104 which, respectively, enable UK ministers to confer additional powers on the Scottish Parliament and (inter alia) to make changes to reserved matters consequent upon ASPs, as well as the greater than anticipated use of Legislative Consent Motions to allow the UK Parliament to legislate on Scotland’s behalf, also point to a co-operative approach to the achievement of legally effective legislation.  Moreover, such inter-governmental co-operation does not appear to be particularly dependent upon political compatibility: the independence referendum apart, there is no evidence, as far as I am aware, of greater disagreement over competence issues between the SNP at Holyrood and the Conservative/Liberal Democrat coalition in London than there was under previous administrations.

Nevertheless, internal policing of the boundaries of legislative competence cannot be the sole reason why so few judicial challenges emerged in the early post-devolution period, nor can it explain why the rate of challenge has increased so dramatically.  There are at least three reasons why political mechanisms cannot be expected to eliminate all potential challenges: first, the government(s) may identify possible legal problems, but for political reasons decide to legislate anyway; secondly, they may identify potential grounds of challenge, but conclude that they are unlikely to succeed; thirdly, they may simply fail to identify relevant competence issues.  Given the complexity of the reserved/devolved boundary, the reach and intricacy of potential EU constraints, and the open-textured nature of Convention rights, it would seem, on the face of it, that there must remain substantial scope for individual challenges.

So what factors might explain the changing incidence of judicial challenges?  These might include:

• Greater awareness of the possibilities for challenge on the part of potential litigants and/or their legal advisers;
• Greater perceived receptiveness of the courts towards vires challenges;
• Reduced financial or other barriers to litigation;
• Increased financial or other incentives for potential litigants to challenge legislation;
• Bolder use of its powers by the Scottish Parliament, particularly in ways that impinge upon powerful interests.

More detailed examination would obviously be needed to establish the relevance of these suggested factors, and to identify other significant considerations.  The likelihood is that different combinations of factors are at work in different cases, and there are of course inherent difficulties in trying to prove a negative – i.e., why challenges have not been brought.  Nevertheless, there is important empirical work to be done in gaining a fuller understanding of the incidence of vires challenges and their motivating causes.  In turn, this would provide a more nuanced appreciation of the practical significance of the Scottish Parliament’s bounded competence, and of the role of judicial enforcement of the devolution settlement as just one policing mechanism amongst others.

Aileen McHarg is Professor of Public Law at the  University of Strathclyde.