Alex Salmond's plans for the armed forces in an independent Scotland could have been written "on the back of a fag packet", according to Ruth Davidson.

The Scottish Conservative leader was quoting from a letter she received from a young soldier due to deploy in Afghanistan in which he slams the First Minister's understanding of how the armed forces operate.

Speaking at First Minister's Questions, Ms Davidson also reeled off a barrage of quotes from senior defence figures who said Mr Salmond has "no grasp" of how the armed forces work and that his party does not "have a scooby" about defence.

Ms Davidson said: "Former commander of the Black Watch, Lieutenant-Colonel Sir Andrew Ogilvy-Wedderburn, said the First Minister had absolutely no grasp on how the armed forces work.

"Lord Robertson, the former secretary-general of Nato, said that the First Minister's plans have no coherence or relevance."

She then quoted Colonel Clive Fairweather, former commander of the King's Own Scottish Borderers and former deputy commander of the SAS, who said: "I have respect for some of the stuff that the SNP has come up with and are proposing but when it comes to defence, I don't think they have a scooby.

"I do find Mr Salmond very, very, very weak on this area. I have watched him. I have been with him. He really doesn't understand it. He doesn't get it."

Quoting from the young soldier's letter, Ms Davidson said: "I am sure you are aware of the phrase back of a fag packet, and this it seems is how Mr Salmond has developed his plans for the armed forces."

The soldier then asked if serving personnel "will be forced to make a choice between the uniform in which they have faithfully served the Crown and in many cases tragically lost friends, and the country of their birth".

Trident

In his response, Mr Salmond said military personnel "will certainly have the choice of which armed forces they would serve".

He said: "At the last count I think there were 23 nationalities serving in the British armed forces at the present moment.

"The issue of choice, of course, is a very valuable one. You see, the forces that are being made redundant at the present moment from the armed forces don't have a choice. They are being made compulsorily redundant by the Government which Ruth Davidson supports, while many of them have been in theatres of conflict. That's no choice at all.

"I met Clive Fairweather when I was marching to defend the Scottish regiments which were being shut down by the Labour Government.

"Nor do I think George Robertson, perhaps, is the strongest suit for the Conservatives. After all, George Robertson said that devolution would kill the SNP stone dead. I don't think that's quite happened."

Ms Davidson also queried the effect the SNP's policy of nuclear disarmament would have on defence jobs in an independent Scotland.

She said: "The Faslane naval base is the largest single-site employer in Scotland, with 6500 people working on the Clyde. The latest MoD figures show that there are 18,000 uniformed and civilian defence personnel based across 30 of Scotland's 32 local authority areas.

"That does not include the 4500 workers in yards in Rosyth and on the Clyde, building Navy destroyers and aircraft carriers, or the thousands of other defence contractors right across Scotland engaged in work of the UK military.

"So we know that the First Minister wants to decimate the 6500-strong workforce at Faslane but how many defence workers, uniformed or otherwise, does he actually plan to keep?"

Mr Salmond countered, saying the cost of replacing for the Trident submarine fleet, estimated to be £100bn, would be far better invested in creating new jobs. The First Minister also noted that Faslane would continue to operate as a base for minesweepers and other submarines in a post-independent Scotland.

He added: "I don't even believe Ruth Davidson would argue that there could be a more sensible investment that would create far, far more jobs than investing in a new generation of Trident submarines."