Every referendum by first past the post is deeply flawed. That's why we need a Final Say on Brexit

Under the Danish system, the UK's 2016 referendum would have to have been ignored

Electing MPs on the basis of first past the post might work for the rough and tumble of Westminster-style politics. It’s unruly. MPs can scrape in on the slenderest of majorities which might represent barely a quarter of their electorate. Occasionally, as it did with Thatcher and Blair, first past the post can produce thumping majorities. It has its strengths and weaknesses. Both Theresa May and David Cameron will testify to that.

But what might clumsily work for representative democracy does not work for direct democracy. Holding a Brexit referendum, or any referendum, based on first past the post is likely to produce deeply flawed results. That’s why the UK traditionally rejected referenda. If referenda are to count, they need to be carefully regulated. When it comes to voting in MPs under the first past the post system, we make do – after all, we know we can vote them out next time. But when we have referenda based on that voting system with no additional safeguards, we’re trapped.

Because the UK perceives itself as a representative democracy, we haven’t done much thinking about referenda and their place in our system of government. They’ve been used successfully in the past, particularly in the context of devolution. First past the post produced Westminster Parliaments that were elected on a clear pledge to create devolved assemblies. Acts of parliament then translated that promise into a reality which was put to the people to either confirm or reject. The people of Wales and Scotland, for example, knew exactly what they were voting for in their respective devolution referenda at the end of the 1990s.

Peace was brought to Northern Ireland through a referendum. The text of the Belfast/Good Friday Agreement had already been agreed by all parties involved in the peace process and was published in advance of their referendum. Both the British and Irish governments held referenda on the same day, in 1998. In Northern Ireland, 71.1 per cent voted in favour of the agreement with a turnout of 81.1 per cent. In the Republic, 94.4 per cent voted Yes with a turnout of 56.3 per cent.

How do you establish best practice for a referendum? Guidance comes from the Venice Commission, the good governance arm of the Council of Europe. (The Council of Europe has nothing to do with the EU: countries from Andorra to Azerbaijan are members of the Council of Europe, as is the UK.)

The Venice Commission’s 2018 Code of Good Practices on Referendums clearly states that a referendum can either pose a general question (that’s what happened in the UK in the 2016 EU Referendum) or give voters a choice between specific constitutional or legislative texts. If a general question is posed, as the commission points out, it cannot be binding unless the rules clearly specify how the result will be implemented.

An interesting feature of the code is that it points out what to do in situations where a referendum is blighted by misinformation or electoral offences. Not only must there be a means to appeal against the result of the referendum, but in the event of such irregularities, the result must also be voided. Once the result is voided another referendum should be held after a reasonable period of time has passed.

Where a referendum will have an impact on constitutional practice and protections, states with a settled use of referenda require multiple safeguards. Good practice demands that both the electorate and the legislature should be decisively in favour of change. For example, in Denmark a constitutional change requires parliament to vote for the proposal twice. Secondly, a general election must happen between the two parliamentary votes. At this stage, a referendum can take place. In that referendum, over 50 per cent of those voting and 40 per cent of the electorate as a whole must support the change for it to be implemented.

Turning to the UK’s EU referendum, it assumed a binary choice between leaving and remaining in the EU, when the reality is far more complex. There were also no minimum safeguards in place for such a major constitutional shift. Those who voted leave were 37 per cent of the electorate. Remain voters were 36 per cent. The rest didn’t vote. Not even the minimum threshold of 40 per cent of the electorate was crossed, let alone the idea of super majorities for constitutional change.

Under the Danish system, the 2016 referendum would have to have been ignored. That was the case with the first Scottish devolution referendum in the 1970s. The 40 per cent threshold was not crossed, which parliament had required. The poll therefore was void. The naivety of David Cameron in applying the first past the post principle to the referendum is the root of the current crisis.

The 2016 referendum was flawed and inconclusive. It’s also mired in misinformation and the whiff of criminality. For these reasons alone it needs to be held again. We don't need a second referendum or a confirmatory one. We need a properly run referendum. Had an effective referendum been held with all the right safeguards in place and one that complied with international law, we could have been saved three years of anguish. And we might have left the EU or confirmed our commitment to remaining.