Do you remember much about the 1997 Scottish devolution referendum? The huge protests, fights in the streets or wrangles with friends? No? That’s probably because they didn’t happen.

In 1997 Scotland voted broadly three to one to establish the Scottish Parliament. There were dissenting voices but the result was never in doubt. The practical effect of the decisive referendum result was to create a full stop to the debate about whether devolution should happen and give the new Scottish Parliament both a popular mandate and moral legitimacy. The referendum actually brought the country together, its very clear result convincing most devolution detractors that they should now work to make it a success.

The 1997 referendum was the right sort of referendum – endorsing decisively what was already broadly supported.

The situation now could not be more different. Roughly a third of our electorate are determined Scotland should leave the United Kingdom and roughly a third are determined it should not.

The key is the other third – fluid, uncertain, open to persuasion. Unless a position is reached in which it is clear two-thirds of Scotland have reached the conclusion they want separation, another referendum would be a disaster for the people of Scotland and the businesses who create the wealth on which those people depend.

Businesses thrive on stability, a stable tax and currency regime, a lack of borders. But there is something business needs even more than these if it is to prosper – it needs a country which is not at war with itself.

Separation from the rest of the UK would be economic madness for Scotland but so too would concentration on the constitution after May 6 this year – war with Westminster and amongst ourselves rather than working together to recover properly from the Covid pandemic. Business, schools, hospitals, social care, infrastructure would all be casualties as politicians fought the battle for the soul of the nation.

What if suddenly Boris Johnson accepted (and I pray he will not) that a majority of one in the Scottish Parliament is sufficient to allow a second-in-a-generation referendum? Scotland would once again be plunged into tribalism which pays for no nurses and no teachers.

What if another referendum was won or lost by one vote? Would that result heal our nation or leave it yet more divided, weakened; bleeding wealth, energy and talent. And only after that point do you start the bruising negotiation with the rest of the United Kingdom if the vote has been for separation or, if the result has gone the other way, to try to reassure in Scotland and outside it that there really will not be a third referendum coming along soon if Nicola Sturgeon’s successor can somehow wangle it.

It is indeed for the people of Scotland and not others to decide whether we stay within the United Kingdom but it is vital that the question is posed again only if and when there is a very clear view amongst Scots that we want separation. To do otherwise risks destruction of prosperity, jobs and public services on a grand scale as well as a legacy of bitterness and division.

What we need is two things. First, that if there is to be another referendum it should only be when a decisive majority of Scotland wants it and, second, the trigger should be transparent and understood.

The Westminster Government should state, now, that it will allow another referendum on the separation of Scotland from the UK if more than two-thirds of MSPs, that is at least 87 of them, specifically vote to request it.

Such a statement should come with two key conditions.

First, in Scottish Parliamentary elections parties should not be permitted to stand for the regional list seats unless they have also stood in all the constituency seats in that region. At the moment only the SNP, Labour, Conservatives and LibDems do this. The rest – Unionists as well as nationalists – play the system, the likes of Alba, the Greens and All for Unity who only stand for the regional list seats are trying to distort the real result and cheat the people of Scotland – this must be stopped.

It follows from this condition that no valid call for another referendum can be made during the next Scottish Parliament. That’s a good thing – renewal and recovery from Covid can be the sole focus of our national attention for the next five years.

Second, the Scottish Parliament must accept that the Independent Electoral Commission would set the question in any further referendum. The 2014 question was scandalously favourable to the nationalists and such gerrymandering must not be allowed again.

In combination, what these measures would do is allow us all to concentrate on what actually matters to the lives of people and businesses in Scotland but also provide a clear path to another referendum if, and only if, Scotland decisively unites behind the view there should be one.

Guy Stenhouse is a Scottish financial sector veteran who wrote formerly as Pinstripe