THOSE of us who heard Sir Nicholas Macpherson's evidence to the Public Administration Committee ("Currency union civil servant defends advice, The Herald", April 10) will have been left scratching our heads.

As you report, Sir Nicholas disavowed any intention to influence Scottish voters; his intended audience was "the British people, the wider world, the markets". Yet he was anxious that his advice should be available before the referendum, and he cannot have been innocent of the uses to which it would be put once in the political arena, or the possible impact on public opinion in Scotland. If the purpose was to end all speculation on the matter of currency union, then the intervention has evidently not succeeded, as contributions to your pages have shown.

The committee's focus is on the role of civil servants during the campaign period of the referendum. Sir Nicholas's intervention raises a more interesting question, which is the role of UK civil servants in the period between a Yes vote, if such there be, and the achievement of independence - especially the role of civil servants in departments, such as the Treasury, responsible for reserved powers. Those departments, as Sir Nicholas conceded, serve the whole of the United Kingdom and will continue to do so. Nick Clegg may tell us that the Government is spending no time considering what might happen in these circumstances, but I would be surprised if the Cabinet Office had not, on a contingency basis, considered the guidance which might be provided to civil servants in the context of the machinery for negotiation. It would make a fascinating read.

Peter Syme,

35/3 East Claremont Street, Edinburgh.

HOW interesting it was to read the expert views of Professor Malcolm Chalmers of the Royal United Services Institute and Lord West, the Former Sea Lord, on the possible relocation of Trident from the Clyde ("Scotland Office minister insists: No deal on Trident", The Herald, April 11). Both conclude that it may be impossible to move Trident to Milford Haven in Wales or Devonport in Plymouth due to public fears and because it would certainly run into public opposition. The Scottish people have been forbidden from having such a choice; Trident was foisted upon us on the Clyde and in close proximity to Scotland's largest city, Glasgow. What a disgraceful legacy to leave our children's children.

Donald J Morrison,

20 Haig Street, Portknockie, Buckie.

NICOLA Sturgeon is correct in her appeal to Labour voters: vote Yes on September 18 and you may get back your party, but vote No and you guarantee continuing London control of the Scottish Labour Party.

In doing so, you are not betraying the Labour Party. It was the Labour Party of Tony Blair and Gordon Brown which betrayed the traditional Scottish Labour voter, and this continues with the policies of Ed Miliband and Ed Balls .

Whether an SNP supporter or not, now is the time for all those who honestly wish a sea change in Scottish politics to make their mark; all the Scottish parties need to break away from the suffocating influence of London autocrats.

It has been made clear during this referendum campaign that the No campaign is driven by the metropolitan perspective. All major pronouncements and gaffes have been issued from there by Cabinet ministers, MPs, Labour and Conservative peers and commentators who see Scotland as a remote and irritating backwater .

Let us grasp this once-in-a-lifetime opportunity to take control of our own political parties. Let the Conservative, Liberal Democrat and Labour parties join the Greens and SNP in speaking up fearlessly for their voters, without always looking over their shoulder to see if London agrees.

James Mills,

29 Armour Square,

Johnstone.

I AM at a bit of a loss to understand the assertion by the National Institute of Economic and Social Research that Scotland would be liable for a £23bn debt repayment in the event of independence even if it was outside a sterling zone ("Claim Scots face £23bn in debt repayments after independence", The Herald, April 9).

The sterling currency is an asset of the United Kingdom and Scotland owns a share of it. Also, as a part of sterling, Scotland owes a share of the national debt.

They are two sides of the same coin. If you unilaterally remove one, then you remove the other.

Sterling is one of the major assets in Scotland's share of the United Kingdom and it would make no economic sense to give it away without a quid pro quo.

Bill Hendry,

6 Blackwood Road,

Milngavie.

My personal knowledge of Spanish history can be written on a postage stamp, but I was interested in your article on that nation's affairs ("Spain rejects referendum call", The Herald, April 9)

My heart went out to the Catalonians when I realised the Better Together Spanish equivalent, Alessandro Del Monte Darlingcida, the man who does not like to say "Yes", will already be telling the 16% of the Spanish population who run one-fifth of the Spanish economy they are not fit to rule themselves, will pay more in taxes, will be disenfranchised as existing EU citizens, will not have the right to automatic EU membership, will not be allowed to retain the euro, their banks will have to re-headquartered elsewhere, they must have border posts on their side of the border, will have to sign 20,000 plus treaties and they will not be able to afford the army, navy and air force that will be needed to protect them from hordes of potential invading Andorrans and vengeful Gibraltarians.

Assuming such entities and other bogeymen exist, the navy will be needed to protect their overfished tuna stocks from invading dolphins, errant Monagesque fishermen and Corsican smugglers and bandits. Oh, and let's not forget the taxes that will be imposed on exports of cuddly toy donkeys and sombrero hats.

All of which will lead to the collapse of western civilisation as we know it. You really can't imagine it happening, can you ?

Ian Wilson,

23 Friarton Road,

Glasgow.

IAIN AD Mann (Letters, April 11) adds to the criticisms of Lord Robertson for his "forces of darkness" rhetoric. However, it remains clear that, while it is hard to identify any parties who would have reason to attack us in force, co-operating in mutual defence agreements as in the UK now gives needed support to others more obviously threatened.

Combatting terrorism is an integral part of this, and smaller countries need more than their own specialist police - larger countries with bigger intelligence networks and resources are necessarily leaders, like the UK.

Going our own way is not the best option!

Joe Darby,

Glenburn, St Martins Mill, Cullicudden,

Dingwall.