“[T]here has been a longstanding resistance, as a matter of law, to the idea that legislative inaction or silence, filtered through a judicial stethoscope, can be made to sound out changes in the law’s lyrics – altering the prevailing patterns of rights, powers, or privileges that collectively constitute the message of our laws.” (Lawrence Tribe, “Toward a Syntax of the Unsaid: Construing the Sounds of Congressional and Constitutional Silence,” Indiana Law Journal 57:4 (1982), Article 1)

Professor Tribe’s observation, though in a somewhat different context, is familiar to those of us who cherish the principle of legality. And yet, to borrow a well-worn phrase, the sound of silence rang through submissions to the Supreme Court yesterday.

Statutory silences are crucial to both sides. For Ms Miller, Lord Pannick contends that Parliament’s silence in the EU Referendum Act 2015 means that the Executive is not empowered to start the Article 50 process. Mr Eadie for the Government relies on the same silence for the diametrically opposed position.

Constitutional silences run through these joined appeals as well. The Supreme Court’s task is made arduous by the UK’s lack of a codified constitution. The balance of powers between the executive and the legislature often goes unspoken, a matter of political reality rather than constitutional orthodoxy. The logically prior question to statutory interpretation, as Lord Sumption was keen to stress on Monday (page 74 of the Day 1 transcript), is what the scope of the foreign affairs prerogative actually is in the EU context. Since there is “constitutional” silence on this, the courts have no choice but to spell it out. Meanwhile, the Scottish and Welsh governments’ position is that the devolved assemblies must be allowed to speak before Article 50 notification can be served – notwithstanding the Westminster Parliament’s silence on this in the 2015 Act.

Let us assume, first, that the prerogative was as extensive as the Government claims prior to the European Communities Act 1972. David Allen Green writes with dismay that the Government “contended that because there had been no law passed by Parliament which prevented the exercise of the royal prerogative in respect of Article 50 then the prerogative was available”.

However counter-intuitive this may seem, it must be right as a matter of principle that if Parliament has not limited the prerogative expressly or by implication, then it remains in place. Mr Eadie’s submissions yesterday, however, sometimes seemed to stray from divining Parliament’s (implicit) intention to the Court itself creating one.

One argument he faced is that the 1972 Act places a “clamp” on the general use of the prerogative (as the Government sees it) on the international plane to withdraw from treaties, because by the 1972 Act Parliament created special, statutory, domestic rights. (Page 25, line 9 of the Day 2 Transcript.)

The Government says that that the 1972 Act is silent, so no such clamp exists. But the Court was urged, in the alternative, to read into the silence of the 2015 Act removal of any clamp. What to make of the idea that Parliament surely expected the Government to act on the referendum result – even if it did not, in terms, spell this out in the 2015 Act?

Per Mr Eadie:

“Given that that [clamp] is a legal construct, given that that is a court imposing, as it were, through a process of implication Parliament an intention, that must be inherently subject to change if the legislation changes … even if [the clamp] is the prima facie conclusion on 1972, that must be inherently susceptible to change. The 2015 Act comes in and its legal effect is to leave or to remove, if you will, by the same process, by exactly the same process of implication, that which you impose by necessary implication now comes off by virtue of the same process.” (Pages 25 to 26 of the Day 2 Transcript.)

This may, to some, seem a troubling assertion. Deciding the a priori scope of the prerogative for itself (based of course on previous cases, if on point) is one thing: the Supreme Court has no choice but to do so. But seizing upon Parliament’s silence in 2015 to displace the (ex hypothesi) correct interpretation of the 1972 Act seems to dangerously conflate two quite different things: the implied meaning of an Act that the Court in good faith considers the best reading, and a true statutory silence that can be used as a fig-leaf to reach the preferred outcome.

Some say that a “one-line Act” to authorise an Article 50 notification is pointless – a waste of time. But I take it as read that we all agree with Thomas Poole on the Supreme Court’s task: “It is not the court’s constitutional role to assess competing options about what the best process to deliver a particular policy goal might be. It is to police the institutional allocation of functions as understood by the constitution.” Removing a “clamp” on the prerogative based on statutory silences – potentially driven by the political reality of a referendum result – risks an outright arrogation of judicial authority.

More unorthodox still, from a constitutional perspective, was another possibility mooted yesterday: that the Supreme Court itself might choose to remain silent. In questioning, the possibility was raised that the Court is somehow constitutionally disempowered to act by the unique political situation that the EU referendum has brought about. Parliament, if it wishes to intervene, can speak at any time: why should the Court require the Government to ask it?

This line of questioning neatly marries statutory silence – in the 2015 Act – and yet another form of constitutional silence – a self-denying ordinance by our highest court. The President of the Supreme Court summarised these forms of silence thus:

“When you get to the 2015 Act, you may say to yourself, picking up Lord Reed’s point about the balance between various parts of the Government, it is not for the court to say what the effect of the 2015 Act is, where Parliament has been very carefully silent, but to say that is a matter for Parliament. And therefore … if it is the case that the 1972 Act has what you call a clamp, the question whether the 2015 Act, which is studiously silent on what its effect is to be, when there is a referendum, should be left to Parliament and not to us…”

Mr Eadie replied, “there are, perhaps because of [the 2015 Act’s] silence, subtle ways in which one can give, as it were, the legal punch line”. (Page 26 of the Day 2 Transcript.)

Indeed there are. But that does not mean to say that all possible “punch lines” are constitutionally permissible. If courts were to stay silent when Parliament could speak for itself, they would stay silent always. And there is surely a principled difference between the most defensible construction of an Act – reading between the lines and working out what was meant, or is necessarily implied, by the language used – and a true statutory silence.

Rachel Jones is a lawyer for JUSTICE. This post is written in a personal capacity and should not be taken to reflect JUSTICE’s views.

(Suggested citation: R. Jones, ‘The Importance of Silences in the “Brexit” Appeals’, U.K. Const. L. Blog (7th Dec 2016) (available at https://ukconstitutionallaw.org/))