AN initiative aiming to invigorate the debate on the economics of Scottish independence gets underway today.

Roger Mullin, a former SNP MP who was a member of the First Minister's Sustainable Growth Commission, is launching a website called The Bottom Line along with fellow economists Professor David Simpson and Graeme Blackett.

The trio, who all support independence, plan to bring their expertise to the discussion in a series of reports and articles examining the costs associated with leaving the UK and why they believe independence will bring economic benefits to the country.

Nicola Sturgeon plans to hold a second independence referendum in October next year using devolved powers. Her Lord Advocate Dorothy Bain has referred the Scottish Government's Referendum Bill to the Supreme Court to find out whether Holyrood has the legal authority to hold the vote.

In June, the First Minister launched the first in a series of papers to update the independence case since the referendum in 2014.

The document, described as a "scene setter", compared the UK's economic and social performance with the higher levels of success of other European countries with a second paper last month examining democracy in the UK.

Later papers will consider specific issues such as currency, what the border would look like with England and Northern Ireland under independence as well as defence and security issues.

The first of the articles on The Bottom Line's website, published today, draws on the science of positive psychology to argue Scotland cannot achieve its full potential while economically dependent as part of the UK. It describes how independence can be the trigger for a virtuous cycle of increased agency to deliver better outcomes for Scotland.

It concludes that Scotland must choose between a state of relative dependency or can embrace the idea of agency and take responsibility for shaping a new future, emulating what has been achieved in other small advanced economies, like Denmark, Sweden, Norway, Finland, Switzerland and the Netherlands.

Future articles will include both quantitative analysis of the performance of the UK (and Scotland as part of the UK) and qualitative analysis, including examples demonstrating the costs of dependency.

Stephen Kerr, the Scottish Conservatives's chief whip at Holyrood, today dismissed the new project.

Wrtiting on Twitter, he said: "A former SNP MP has set up a new blog to "invigorate and elevate" the so-called economic case for breaking up the UK.

"The first entry? "Scotland is helpless in the UK and Indy automatically makes it all better". All going well..."