“OBVIOUSLY there is a red line, which is we want to hold the Union together. That’s very important. But otherwise I am open-minded as to how we make the positive case for the Union.”

So said Sir Keir Starmer, Labour’s UK leader, on his visit to Scotland last week. This is not a particularly new sentiment and has, in effect, been the official Labour party policy since Sir Keir became leader and asked former Prime Minister Gordon Brown to review the structures of the UK and recommend an enduring solution.

The consequences, however, are widespread, and may very well prove to be the central determinant of whether or not the UK remains united.

There is good reason to believe that Sir Keir will match his words with action. Labour has a history of leading people on constitutional change, rather than being led by them, the most obvious example of which is the creation of the devolved parliaments and assemblies in the late 1990s.

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A fortnight ago on these pages, I wrote that Labour was the true party of the Union, and by all accounts I rather upset many of my erstwhile colleagues in the Conservative offices in the Scottish Parliament. I made the point because shouting “no to indyref 2” and waving Union flags may be enough to carry the Tories through an election campaign, but it is not a strategy to repair the ties that bind the Union together.

The Union is not struggling because people are magnetically attracted to independence. The Union is struggling because not enough people think it is working for them.

Labour seems to understand this, and displays the opposite trait to that of the Tories. They do not have the absolutist rhetoric to find a place on centre-stage at an election campaign, but they are working on a long-term solution.

All of that being said, Sir Keir should be careful not to back himself into a corner. On the same visit as he pledged this fast, decisive devolution of more power, Sir Keir said: “We need change without a referendum”. This is a mistake.

I completely understand the reticence towards another independence referendum of those on the Unionist side of the fence. They are scarred by what happened in 2014. They are worried about the effect on society, which was unquestionably split and which has not yet fully healed.

They are anxious about the effect on the economy – political uncertainty is bad for investment and bad for business. Most of all, they are petrified that they might lose, after what they regarded as an unexpected near miss eight years ago.

By ruling out a referendum and instead simply enacting a manifesto commitment, Sir Keir (and Mr Brown, whom I suspect influences this aspect of the strategy very considerably) could suppress the constitutional unrest in Scotland. He could push pro-UK polling up a little, and pro-independence polling down a little. And he could avoid another independence referendum. At least for a while.

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However, presuming that Labour wants to close the lid on this issue, lock it, and throw away the key, it is highly unlikely to achieve that objective without a second independence referendum.

There is something purgative about not being involved in party politics, or indeed in the overly emotional environment of constitutional politics. It offers a clarity which I often find is absent amongst those in the bubble.

It is clear now, to most people, that Scotland has some long-term, structural problems in its economy, in the way it delivers public services, in its transport infrastructure, and so on. And it is equally clear to me that we will not be able to tackle these issues, or even to talk about them, until we have stopped talking about the constitution.

And, in the final analysis, there is simply too large a section of the population who will need this question answered by way of a referendum rather than by way of a manifesto commitment in a general election.

The question is, how should it be done? The answer lies in a multi-option referendum. As well as being, self-evidently, the only way to give those who believe in independence, those who believe in the status quo, and those who believe in home rule (or whatever we want to call the previously-named ‘devo max’ option) a voice, it is also the structure which is most likely to yield the sort of clear, unambiguous outcome which would allow the key to be thrown away, one way or another.

The logical structure, which has been ‘gamed’ by former Reform Scotland Chair Ben Thomson, would be to have two questions rather than one.

The first question would be something like: “Do you support further constitutional change or do you wish to maintain the current arrangements”.

A majority in favour of maintaining the current arrangements would render the second question irrelevant, much as a vote against devolution in 1997 would have rendered the outcome of the tax-varying powers question irrelevant in that referendum.

However a majority in favour of further constitutional change would mean that the outcome to the second question (on which people would be entitled to vote even if they have voted against further change in the first question) would be decisive. The second question would be something like “Do you support independence or home rule”, with the definition of ‘home rule’ being established, presumably, by the Labour government in advance of the referendum.

Independence campaigners, themselves, gave a strong signal last week on what the result of such a referendum might be. When Chris Hanlon, the SNP’s policy convener, mooted something similar to this option, he was publicly and brutally stamped on by a number of senior SNP figures.

Why? Because they, like I, expect that the home rule option would win a referendum relatively comfortably, and would effectively end the prospect of independence.

It is curious, isn’t it, that the thing nationalists are afraid of – home rule in a referendum – is simultaneously something the unionist community seems so reluctant to do.

Perhaps we should not be surprised. It would hardly be the first time the unionists had missed a constitutional open goal.

Andy Maciver is Director of Message Matters