By Matthew Psycharis

PhD Candidate (Law), University of Cambridge; Supervisor of Constitutional Law, Robinson College, University of Cambridge

A referendum is simply a mass, public vote, usually held on a single question.  For example, ‘should the United Kingdom remain a member of the European Union?’  Or, ‘Should Scotland be an independent country?’ 

In the UK, legislation is usually needed to hold a referendum. Normally, Parliament will pass an Act which sets-out the referendum question and the people entitled to vote. The more formal aspects of the vote (like counting procedures, campaigning, and financing) may be regulated by the Political Parties, Elections and Referendums Act 2000.    

This means referendums in the UK are flexible. There are few strict rules about (a) when they should be held, (b) what topic or issues they should address, or (c) who should be allowed to vote. This means they can be used to solve many different political or constitutional problems.   

What is the legal status of a referendum result?   

In the UK, referendums are not legally binding on Parliament. Even if a majority of people who vote in a referendum support a particular policy, Parliament will not be legally required to implement that policy. This is because Parliament is considered to be ‘sovereign’. It cannot be bound either by itself or any outside actors (including through a popular vote).  

Even though referendums are not legally binding, this does not mean they are constitutionally unimportant.  The Supreme Court has also observed that while referendums are only advisory, ‘it would [still] be difficult for Parliament to ignore a decisive expression of public opinion’ (quoting from the House of Lords Select Committee on the Constitution).   

Why bother holding a referendum? 

There are at least three reasons why referendums can be constitutionally useful, while not legally binding.   

First, it can sometimes be useful to isolate a single question for determination by the voting public. Ordinarily, when we vote for a Member of Parliament in a general election, our vote is presumed to authorise that MP’s political party to purse a broad range of manifesto policies (should the party win a majority of seats in Government). However, sometimes, a party cannot agree within its own ranks about the solution to a divisive issue — and so a vote for that party is not a vote for any particular position on that issue. In other cases, an individual voter’s views on a particular policy might be at odds with the views of the political party they normally support. In these instances, a referendum isolates the single issue, and better captures individual preferences than the electoral process alone.   

Second, the political disagreement might be on such a fundamental issue, that some people think it can only be resolved legitimately by a referendum.  Some commentators believe it is now a matter of political convention that referendums must be held before Parliament makes changes on certain ‘fundamental constitutional issues’. These issues might include devolution, the status of the Crown, or the method by which we vote. In these cases, a referendum provides important political legitimacy to any subsequent legal steps taken by Parliament to deliver that fundamental change.   

Third, referendums might be used to help ‘entrench’, or cement, existing constitutional arrangements.  For example, section 63A of the Scotland Act, says that the Scottish Parliament ‘shall not be abolished’ by Westminster unless approved at a referendum. While this is not likely to be legally binding (i.e. an Act could still be passed in Westminster purporting to abolish the Scottish Parliament), it does create a strong political assumption that this should not occur unless a referendum was held first. In a flexible, uncodified constitution like the UK’s, this is one way of achieving a degree of fixity.   

The past, present and future of referendums 

Referendums are not new things in the UK. In the late 19th century, leading politicians advocated for referendums to be held on a wide range of issues: from Irish independence, to women’s voting rights, to import tariffs, and state ownership of infrastructure. In each case, however, a political resolution was otherwise reached, and a referendum was not needed to be held.   

The first national referendum was held in 1975, on whether the UK should remain a member of the European Communities (the predecessor of the EU). Since then, various referendums have been held on the question of ‘devolving’ further powers to the UK’s constituent countries. In 2014, a referendum was held on Scottish independence.   

The proposed 2023 Scottish independence referendum sits within this tradition, but is potentially unique.   

It was explained above how the Parliament in Westminster will usually pass legislation to make a referendum happen. As a ‘sovereign’ Parliament, it can do this.   

However, the Scottish Parliament is more constrained. It is a devolved legislature, given broad, but ultimately limited, legislative powers under the Scotland Act 1998.  Legally, under the Scotland Act, the Scottish Parliament cannot enact legislation on something that ‘touches on’ a constitutional matter.  As Alison Young explains in a recent post on this site, it is arguable that the future of the Union ‘touches on’ a major constitutional matter.   

However, here lies the double-edged character of the referendum. As we have seen, referendums are politically advisory only, and not legally binding. The Scottish Government has already said that their 2023 referendum will only be advisory. Without causing any immediate legal effects, it remains arguable that the vote would therefore not ‘touch upon’ the constitution in any meaningful way.   

However, the other side of the coin tells us that referendums are powerful political devices, that speak to important values within the political half of the constitution and are held precisely to precipitate legal change. Viewed in that way, it is arguable that the Scottish Parliament would be beyond its powers in legislating for a vote.   

No one knows what the answer is.  

In 2014, this problem was solved by the Scottish and UK Governments agreeing to a temporary transfer of power to Scotland to hold a vote, under section 30 of the Scotland Act.  While such agreement may still be possible, it seems very unlikely now.   

The other solution is that the Scottish Government ask the Lord Advocate — who provides legal advice to the Scottish Government — to refer a ‘devolution issue’ to the UK Supreme Court.  The Supreme Court might then give an authoritative legal answer to some of these difficult questions, including whether the Scottish Parliament has the power to cause the vote to happen. This process is now on foot. But, as Alison Young explains, the result of that referral is far from certain, and it may be that the Court declines to hear the reference altogether.   

If the Court decides that the Scottish Parliament has the required power, then the vote gets a legal ‘green light’ and can be held. In that case, the vote becomes like the previous exercises explained above; a powerful, but non-binding, political tool that might encourage subsequent legal change.   

If, however, the Court decides that the Scottish Parliament does not have the power, then the Scottish First Minister has said that the next Scottish elections will serve as a de facto referendum on independence (with the incumbent SNP campaigning on a platform of independence). What happens from there is difficult to judge.   

The main point 

Over the coming months, the main thing to remember is that, in the UK, referendums are a political means to an end. The UK Parliament can hold referendums whenever it wishes, however the devolved legislatures face limitations. It is for the reader to conclude whether this is a good thing, or whether there is a risk of abuse of these political tools: either by actors in Westminster, or in the devolved countries.