YOU know that Scotland had a referendum on independence in 2014. You’ve heard a lot of talk about Indyref2, not least from the SNP. But what about Indyref3? Don’t choke on your porridge because this has come not from Nationalists, but from a former Conservative prime minister who has been one of he leading unionist voices for a quarter of a century: Sir John Major.

In 1995, as PM, Sir John said that a referendum on Scottish devolution would be “the most dangerous proposition put before the people of Britain”. Now he has become the first heavyweight Conservative to break ranks and actually call for a repeat referendum on independence. Incredible. No one saw this coming, certainly not the SNP. Tory MPs are furious that he has legitimised a referendum that Boris Johnson says should wait a generation.

Only Sir John isn’t happy with just one Indyref2, he wants two of them. The first would be a consultative ballot on the principle of starting negotiations on Scotland leaving the UK. The second would be on the actual deal. “Scottish voters would know what they are voting for,”, he told a bar association in London . “And be able to compare it with what we now have.”

Sir John has clearly modelled this on the campaign, supported of course by our own Nicola Sturgeon, for a repeat referendum on Brexit, a “People’s Vote”. That went south with the Tory landslide in December, but he thinks the idea of a double-headed referendum would now work for Scotland. Well, Ms Sturgeon could hardly reject it out of hand could she?

She would of course – the SNP policy is for a one-off referendum on independence after the 2021 Holyrood elections. But it might actually be worth the SNP talking up Sir John’s idea, at least tactically. Why? Because if it ever happened a double referendum would make independence more likely, not less.

You have to look at this from the point of game theory. As the first indyref2 approached, the SNP would say: “Look Scots. It’s independence – you know you want it. Vote yes to the first referendum, because you can always have second thoughts later”. It’s like one of those reserve-and-cancel holiday booking offers.

This would maximise the independence vote in the ballot of principle because people would have nothing to lose. Instead of forcing people to think carefully about the ins and outs – as theydid in 2014 – they could vote with their hearts. It would be like the World Cup. There would likely be tartan fever across Scotland.

It would become a mark of national pride to vote for self-government even if you didn’t really believe it possible. Scots would likely vote Yes by more than the 55 per cent or so that the opinion polls indicate right now. It might look more like the landslide for devolution in the 1997 referendum, which also looked like a no-lose offer.

But wouldn’t that be followed by buyer’s remorse, just like in the 1978 World Cup when Scotland was outplayed and outclassed in the play-offs? Humiliation. Negativity. Chastened Scotland comes back with its tail between its legs desperate to vote Remain in Indyref3? Almost certainly not. Think of Brexit again.

If the experience of Brexit is any guide, the negotiations on Scottish secession are likely, as Sir John says, to be a nightmare. Hard border, customs posts, trade disruption, Barnett subsidies ending. The Scottish Government would have to say what currency Scotland would use after independence and the UK Government would say: “not sterling”.

There would be debts to divide, awkward questions about defence, the BBC. Scotland would be out of the European Union and Brussels, to discourage separatist movements in countries like Spain, would not be trying to make re-entry into the European Union look easy. Firms like Standard Life and Royal Bank would relocate; English people would leave; the independence movement would probably split between the Yes left and the centrists of the SNP.

You might think that, at the end of two torrid years, and with no clear deal decided, the Scots would be relieved to vote No to independence in the second referendum. The Union would be vindicated. Nationalism would be killed stone dead. Oh no it wouldn’t.

Contrary to what Sir John appears to believe, there is no evidence that a second Brexit referendum would have led to a Remain victory, despite the chaos since 2016. In fact, the result would probably have been a bigger vote for Brexit. We know this because the December 2019 General Election was, in effect, a second referendum on Brexit. All the opposition parties were calling for one in their manifestos, even Labour (though Jeremy Corbyn refused to say which side he’d campaign for). Yet the result was an 80-seat majority for Boris Johnson – an extraordinary vindication of his Government’s pretty disastrous handling of the Brexit negotiations.

All the scares about Russian interference, about hard borders in Ireland, lorry parks at Dover, the pound plummeting, Donald Trump privatising the NHS and pushing chlorinated chickens into the supermarkets of Britain... none of it stopped people voting for the politician most personally responsible for Brexit: Mr Johnson. The unionists should have learned from 2014 and 2016 that, in questions of national identity and sovereignty, economic considerations are marginal. Project Fear doesn’t work when nationhood is at stake.

Scottish voters would say they had already made their views known in the massive vote for the principle of independence, and that the UK Government should have tried to implement that result in good faith instead of trying to sabotage negotiations by telling Scots, in terms, that they’re too wee, too poor, too stupid to be independent. When you tell people that they can’t stand on their own two feet, the first thing they’ll do is stand up to prove you wrong.

The idea of a double-headed referendum was originally proposed by Professor Robert Hazell of the Constitution Unit at UCL in 2008. It came after the Scottish Labour leader, Wendy Alexander, made her famous “bring it on” call at First Minister’s Questions on a referendum. In the unlikely event that his cunning plan is adopted, the SNP should say: bring it on, times two.

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