Only two years ago, 55 per cent of Scots voted to remain in the United Kingdom, which was then part of the European Union. Since then, Britain has decided it does not want to be part of the EU, so Scottish nationalists now want another vote. If their fellow Scots agree, they should get it. Just not yet.

Scotland has legitimate concerns. Some 62 per cent of Scots voted to stay in the EU in the June referendum on Brexit, compared with 48 per cent in the UK overall. Meanwhile, British ministers are signalling they will prioritise curbing immigration over access to the single market, and Prime Minister Theresa May is packing her negotiating team with Eurosceptics.

Britain should not deny the Scots another referendum if they demand one. By now, however, the dangers of such votes are clear. Despite the different outcomes, the 2014 Scottish independence campaign was depressingly similar to the Brexit debate this year. Both were short on economic facts, long on political scaremongering and damagingly divisive.

Surely the main issue over any proposed departure from Britain is economic — and what has happened since 2014 reinforces the risks of going it alone. Scotland is reliant on trade with Britain, the main market for the bulk of its £76 billion (about $92 billion) of exports.

By far the bigger economic challenge, however, is the collapse in oil prices. Scotland’s share of North Sea oil revenue was £83 million in 2015-16, down from £2.25 billion a year earlier. As a result, its budget deficit for the most recent fiscal year was 9.5 per cent of gross domestic product, more than double the British shortfall.

Finally, there is the question of exactly what Brexit will look like — and here, it is just too soon to know. True, the rhetoric from 10 Downing Street is at worst discouraging and at best confusing.

But the final shape of the agreement, which will not be known for several years, is relevant to any debate over Scottish independence. Besides which, it is not at all clear that a vote to leave the UK will automatically mean Scotland gets to stay in the EU.

The abiding desire of many Scots for independence is not just about economics, of course. But it is essential that Scottish voters be fully informed about the potential economic consequences of secession.