IS David Torrance having us on ('It's a no brainer: the UK is better off staying in the EU', Herald, 1 February)? Does he believe that, as a Unionist, he must try to justify staying in the EU because there is an equation of that position with one of Scotland staying in the UK? There is not.

What might actually happen if the UK as a whole voted to leave the EU, but Scotland voted to stay? What would the SNP do if Westminster (as is its sovereign right and its constitutional obligation to all UK citizens) were to deny its demand for a second independence referendum, on the grounds that voters should know the final settlement of the UK withdrawal negotiation? To remain within the law the SNP would have to comply just to maintain use of sterling and of fiscal transfers from London, because a UK withdrawal would take several years to complete, and might involve a second referendum on the final settlement.

The second big question would be what, if anything, would a separate Scotland eventually get from the EU that would justify separation from the UK? It would have to adopt the euro because it would have left the UK and would not be allowed, under EU and Bank of England rules, the ongoing use of sterling. The euro will be secure only when it is supported by a political union and a banking union. Similarly only a political and banking union would ensure fiscal transfers to replace some (but nowhere near all) those from London, and also confirm (at a price of higher interest rates) the money market credits to plug the yawning gap between SNP welfare and public service promises and Scotland's home-generated tax revenues. “Independence in Europe” would have gone up in a puff of smoke. Remember Greece?

The third big question concerns immigration. The great majority of the millions of incomers to the EU are Muslim economic migrants. The Brussels bureaucrats and Germany want to abolish the Dublin Agreement which currently allows the deportation of immigrants to the EU countries of their first arrival, as Sweden is now going to do. This rule change would inevitably ensure that those recipient countries would issue EU passports, which would allow the migrants freely to go anywhere in the EU. So would the Nationalists want to be in the EU and have no controls over this country's borders, when rUK, outside the EU, would have border controls and, more to the point, have them from Carlisle to Berwick?

The EU is becoming more trouble than it is worth, especially when, as many countries in the world show, it is not necessary to be a member to be just as prosperous. Why does the SNP so hate the UK and prefer the EU, when the latter has no obvious political and economic advantages? Because it prefers Scotland to be a minnow, not a big fish, of the EU.

Richard Mowbray,

14 Ancaster Derive, Glasgow.