TODAY'S eagerly awaited White Paper will answer the key questions people have been asking about the SNP Government's proposals for Scottish independence, Nicola Sturgeon, the Deputy First Minister, predicted ahead of this morning's high-profile launch.

Scotland's Future - Your Guide to an Independent Scotland will "show clearly and simply the difference we can make in Scotland if decisions on Scotland's future are taken by those who care most about Scotland - that is the people of Scotland," she said.

"Our message to the people of Scotland is simple," Ms Sturgeon added, "read this guide, compare it with any alternative future for Scotland and make up your own mind."

The launch at Glasgow's Science Centre will have a global audience with more than 200 accredited international journalists from as far afield as America, Russia, the Middle East and China.

The tablet-sized White Paper runs to 670 pages and more than 170,000 words. Some 200 pages are devoted to answering 650 specific questions about independence.

It has an initial print run of 20,000 and can be downloaded as an e-book.

It is said to have been made as "reader-friendly as possible" but SNP sources claimed it was ­written in "civil service-speak", suggesting it might not be as user-friendly as intended.

At the heart of the White Paper will be the Scottish Government's main assertion that independence will benefit Scots economically.

First Minister Alex Salmond has insisted the prospectus for independence will present a ­"positive plan for job opportunities and economic growth based on Scotland's vast natural resources, key growth sectors and human talent".

But this morning the Treasury sought to present a different picture, suggesting the price for independence would be an extra £1000 per year on every Scot's tax bill.

In a letter to Mr Salmond, Danny Alexander, the Chief Secretary, says his department's analysis - based on the most optimistic assessment by the Institute for Fiscal Studies - shows by 2021 the average basic rate taxpayer in an independent Scotland could face an extra tax bill of £1000 a year to fill a fiscal black hole.

Mr Alexander points out how the think-tank suggested public sector net debt for an independent Scotland could rise to more than 100% of national income by the early 2030s and to more than 200% by the early 2060s.

"This is not a sustainable ­position," declares the Chief Secretary, pointing out that, even under the most optimistic scenario, the IFS suggested an independent Scotland would have to find "permanent tax rises or spending cuts" equivalent to £3bn a year by the start of the next decade.

"This is a very stark reminder of why it is in the interest of Scotland to pool these risks and not to go it alone," says the Liberal Democrat Highland MP.

He points out how the IFS ­calculated it would take a hike of around eight percentage point increases in the basic rate of income tax to fill such a fiscal black hole.

Mr Alexander said: "I asked Treasury officials to look at this. They calculate an eight percentage point rise in the basic rate of income tax would mean an average increase for basic rate taxpayers in Scotland of around £1000 per year."

But a spokesman for John ­Swinney, the Scottish Finance Secretary, rubbished his claims, saying his "rushed and panicky" letter showed "just how rattled the No campaign are by the launch of the White Paper and its positive vision for Scotland's future".

He claimed the Chief ­Secretary's sums were "all over the place", noting how earlier this year he had claimed independence would cost every Scot just £1 a year. But the reality is the policies of his Tory-led Government have cost many ordinary Scots far more than £1000 each since they came to office."

The spokesman added: "Only independence will give us the chance to change things for the better, creating jobs, boosting growth and delivering a more prosperous and fairer country.."

Meanwhile, Alistair Carmichael, the Liberal Democrat Scottish Secretary, visited visited Nairn's oatakes in Edinburgh as he kept up his profile following his weekend appearance on the Andrew Marr Show.