THE former SNP leader, Gordon Wilson, former deputy leader Jim Fairlie and the leaders of the Greens and the Scottish Socialists, Patrick Harvie and Colin Fox, disagree with Alex Salmond over keeping sterling ("Further backing for new Scottish currency", The Herald, April 30).

They are correct that a new national currency would mean a sovereign monetary and fiscal policy. But the consequence would be an extreme volatility in the balance of trade and in the value of the currency.

If oil output rose to the levels which the SNP recently forecast, a rising currency would make imports cheaper and consumers better off. But cross-Border shopping trips to England would seriously undermine small retailers in Scotland. The high currency would devastate Scotland's manufacturing, agricultural and service exports. The employment effects and economic adjustments would be far more severe in a small economy than were those caused in the UK after the 1978/79 Opec oil price hike. The opposite effects of a falling currency would occur with similar rapidity in the event of a fall in oil production.

However, Mr Salmond's idea of a sterling zone is just as flawed. Because the rest of the UK comprises 91% of the current entity, it would matter very little if, in a petty-minded fit of pique, Mr Salmond abrogated taking on Scotland's share of the national debt and of the bank bail-outs. The latter are largely liabilities which are off-balance sheet and are not included in the national debt. As the banks recover, liabilities will fall and even possibly become assets. But the consequence of such actions by Mr Salmond would be to turn a newly independent Scotland into an international pariah.

As for joining the euro, that is off the wall.

Harry Reid ("United we will stand – but for how long?", The Herald, April 30) is similarly at sixes and sevens. In the event of a No vote in the independence referendum of 2014 and a Tory win in the 2015 UK General Election, he posits the escapist fantasy so beloved by the Scottish left: that in a referendum in 2017, Scotland will vote to stay in the EU while England votes to walk away.

Scots and English equally abhor the euro and its crippling consequences for the poor and unemployed across Europe. Why would they vote to stay in an EU that does that to its people? Why would they need to stay in the EU if the whole euro and integrationist project collapses before 2017?

Iain Paterson (Letters, April 30) correctly bewails austerity but fails to point out that it is an EU phenomenon. In the UK we have had no austerity, just stagnation. Our budget deficit is £120 billion a year and our national debt has risen to £1.2 trillion. Yet Mr Paterson has consistently argued for more borrowing despite the baleful consequences for our children and grandchildren. Furthermore, like most Nationalists, he would want an independent Scotland to remain in the EU.

Independence would turn our families and friends in England, Wales and Northern Ireland into foreigners. It would mess up our defence and security. It would lead to an even more socialist Scotland than we currently must endure. It amazes me that, with all the confusion and disturbance to our lives that independence would entail, as many as 30% of Scots can even contemplate it.

Richard Mowbray,

14 Ancaster Drive, Glasgow.