Scottish independence will hit the average Scot with an extra £1,000 on their yearly tax bill if the country ended up voting "Yes" in next year's referendum on whether to break the union with England.

According to UK Treasury secretary Danny Alexander, the average Scottish taxpayer would be £1,000 a year worse off due to an 8% tax rise in the basic rate of tax that they would have to pay.

Currently there are more than 2.4 million basic rate taxpayers in Scotland, who in total contribute some £6.1bn (€7.3bn, $9.9bn) in income tax, according to Treasury figures.

UK government analysis shows that they currently pay an average of £2,517 a year.

Yet, the Treasury research suggested that if the basic rate of tax was increased from 20% to 28 %, this would rise to £3,523 a year - an increase of just over £1,000.

These calculations were based on the findings of a report published by the Institute for Fiscal Studies (IFS) which said any Scottish government would have to implement tax hikes or spending cuts and even both to balance the books in an independent Scotland.

Alexander's remarks towards Salmond and his policy claims were scathing.

"This is a very stark reminder of why it is in the interest of Scotland to pool these risks, not go it alone."

"Even under the most optimistic scenario the IFS considered, in 2021-22 an independent Scotland could have to find permanent tax increases or spending cuts that would be equivalent to £3bn in today's terms," Alexander wrote in a letter to the SNP leader.

"I asked Treasury officials to look at this. They calculate than an 8% point rise in the basic rate of income tax would mean an average increase for basic rate taxpayers in Scotland of around £1,000 a year," he added.

A spokesman for Scotland's finance secretary John Swinney said Alexander's letter was "rushed and panicky" and showed "just how rattled the No campaign are by the launch of the White Paper and its positive vision for Scotland's future".

"Danny Alexander's sums are all over the place - earlier this year he was claiming independence would cost £1 per person a year, but the reality is, the policies of his Tory-led Government have cost many ordinary Scots far more than £1,000 each since they came to office," the spokesman continued.

"And for Danny Alexander of all people to cite the IFS almost beggars belief. It is the failing policies of Alexander and his Treasury colleagues which the IFS's forecasts are based on - forecasts which show the UK in fiscal deficit for every one of the next 50 years.

"Westminster's waste has also squandered oil revenues which could have been put in a national savings fund now worth up to £22,000 for every person in Scotland.

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