Image caption John Swinney and Alistair Darling were speakers at The Scotsman conference

Scotland's Finance Secretary John Swinney has said successive Westminster governments failed to maximise the potential of Scotland.

He made the claim during a debate on the economics of Scottish independence.

Arguing in favour of the union at The Scotsman newspaper-run conference was former UK chancellor Alistair Darling.

He had earlier told BBC Scotland that it was nonsense for an independent Scotland to keep sterling as its currency.

SNP government minister Mr Swinney told the gathering that over the past 30 years up to the financial crisis, "growth in Scotland had averaged 2.1% against 2.7% in other comparable small EU countries and the wealth we have delivered for the UK has not been shared".

Analysis Corporate Scotland has been slow and reluctant to step up to the independence debate, but it's beginning to make its presence felt. And the area where it's focussing a lot of attention is on the cost, the pace and the complexity of the transition. At a conference hosted by The Scotsman newspaper on Tuesday, finance secretary John Swinney set out the case for the powers to tackle inequality, and to pick up on the economic opportunities that Westminster rule has missed. But while there's a lack of any alternative prospectus, of a vision for what the UK could deliver Scotland if it votes to stay where it is, it's the 'yes' side that's taking the pressure - not on the vision, but on the means of getting there. Contributors are keen to keep some perspective. Business-people are being kept awake by the eurozone crisis at the moment, far more than concerns about independence.

He added: "Such figures are all the more frustrating as despite a period of unprecedented growth in the global economy, the previous UK government missed a once in a lifetime opportunity to deliver a real improvement in prosperity and social equality.

"Instead, growth was squandered on an unsustainable boom that benefited the few rather than the many."

He believed Scotland had the means to meet the "ambitions of the people of Scotland and would deliver a better future".

Mr Swinney said the country had;

assets in the form of renewable energy with 10% of Europe's wave energy, 25% of its tidal energy and 25% of its offshore wind resources.

and a "strong intellectual base" with strengths in the areas of science, engineering, technology and financial services.

But Scottish Labour MP Mr Darling, who is head of the cross-party campaign to keep the UK together, has insisted that independence comes with economic risks.

In an interview with BBC Scotland's Good Morning Scotland programme, Mr Darling focused on the SNP's assertion that an independent Scotland could keep sterling currency.

He said: "What you would have with independence is two separate countries, Scotland and the rest of the UK, rather like you have Germany, Greece and Spain, for example.

"You would have a common currency and a single central bank - all this is having to be done without, so far, planning to ask the rest of the country what it thinks about it.

"But even if you got agreement to do that it means you then have to have a eurozone style system where you submit your budget for approval to make sure you are borrowing in line with everybody else. That is not independence.

Media playback is unsupported on your device Media caption Alistair Darling: "If you have a common currency, it takes you inevitably to economic union and then political union. What is the point in leaving the UK only to come back a few years later?"

"It makes absolutely no sense and the key thing is that, as we see in Europe, if you have a common currency it takes you inevitably to economic union and then political union. What is the point in leaving the UK only to come back a few years later with effectively political union again - it is just nonsense."

Former Scottish Liberal Democrat finance spokesman Jeremy Purvis, leader of the Devo Plus campaign, spoke at the conference of fiscal policy options for Scotland, short of independence.

The conference was also scheduled to feature speakers from academia, business, finance and the media.

John Kay, visiting professor at the London School of Economics and a Fellow of St John's College, Oxford, discussed "the big economic picture" surrounding independence.

The potential future of North Sea Oil in an independent Scotland examined by Alex Kemp, professor of petroleum economics at the University of Aberdeen.

Institute of Directors Scotland chief executive David Watt gave a business perspective on investing in an independent Scotland, while Scottish Financial Enterprise chief executive Owen Kelly conducted "a search for facts and evidence" on the future of financial services.