Mr Ahern said comments made during an interview had been sensationalised and left open to misinterpretation and he was disappointed that he had been portrayed as opposing Scottish independence.

He said that rather than facing serious economic problems, Scotland would be better positioned to prosper than Ireland was when it gained independence.

In a letter to First Minister Alex Salmond, Mr Ahern said: “I want to assure you that I most certainly did not use pejorative terms such as ‘split from the Union may spell disaster’ and ‘Scottish independence could spark an economic catastrophe’.”

The remarks were seen as an embarrassment for Mr Salmond, who has often used the Irish example as a model for an independent Scotland.

Mr Ahern said the “essential point” he had been making was that in any debate about sovereignty, long-term economic consequences would come to the fore.

He said: “I said in my interview my only proviso about the step to full Scottish independence is the cost factor, and I said your country’s best economic experts should analyse this.

“I think this is important so people can make their own informed decisions on the economic consequences or benefits of independence.”

Mr Ahern, who headed the Irish government until last year, said the Scottish economy was robust and able to compete in a globalised world and was an integral component of the European Union.

He added: “It is an inescapable fact that the prevailing conditions are such that a post-independence Scotland would be in a much better position to thrive rapidly, and certainly far quicker than Ireland could have when we first gained our independence.

“It took time and commitment over many years to build-up the Irish State into a model of economic success.

“I have no doubt that the Scottish people have the same ingenuity and commitment to achieve huge success should they decide to go down the route of full independence.

“That, however, is a matter for the Scottish people to ultimately decide and, as an Irish politician, I think it is best for me to not immerse myself in another country’s debate.”

Mr Ahern also said he stood by his comment that devolved government within the UK had delivered “many positives” for Scotland.

He added: “I am disappointed that some newspapers have tried to portray that as me in any way opposing full Scottish independence.

“It is for the Scottish people to chart their own destiny and to make their own decisions.”