A former head of the British Army has said he fears a Yes vote in the Scottish referendum could be "letting down" Scottish soldiers who died during fighting in Northern Ireland.

Lord Dannatt, who was chief of the general staff between 2006 and 2009, made a personal plea to Scots for a No vote in the Sunday Telegraph, stating more than 100 Scottish members of the armed forces had fought and died defending the UK during the Troubles.

He said: "Do the families of Scottish soldiers who lost their lives between 1969 and 2007 to preserve the territorial integrity of the United Kingdom now just say, "Well, it no longer matters"?

"I cannot speak for them, but I wonder just how much thought, appreciation and recognition is given to the memory of those who have fought and brought this United Kingdom of ours to where it is today, and where it could be in the future. And I really worry on behalf of the wives, mothers and friends of those Scottish soldiers who died to keep Northern Ireland in the United Kingdom.

"I worry particularly about the extent that we will be letting them down if Scotland disappears from our country, just on the whim of a few thousand voters willing to gamble on an uncertain future rather than staying within the United Kingdom, whose track record is second to none in Europe."

Lord Dannatt added he felt defence was the "weakest link" for an independent Scotland.

It comes after a host of senior military figures have raised concerns about independence in relation to the country's defences in the months leading up to the crucial vote, with former Nato commander General Sir Richard Shirreff even branding it "dangerous".

But Angus Robertson, the SNP's defence spokesman, responded: "A dangerous and amateurish defence policy would be one that sent troops into an illegal war without proper equipment, while wasting tens of billions of pounds on Trident nuclear weapons that can never be used - that's the UK."

Shadow foreign secretary Douglas Alexander dismissed the remarks.

"I am unyielding in my admiration and respect for the men and women of the British armed forces and the contribution that Scots have played and continue to play in those forces," he told Sky News Murnaghan programme.

"But many British soldiers have given their lives over the years to defeat fascism and then to defend democracy and let's be absolutely clear: what we are witnessing here in Scotland on Thursday is an exercise in democracy.

"So I hold no brief for Lord Dannatt this morning."

Scottish Deputy First Minister Nicola Sturgeon said the former military chief's comments "bordered on being offensive and insulting".

"There are mixed opinions across the armed forces as there are across Scottish society."