THE cost of being economically “tethered” to Britain has cost Scotland about £64bn over the past three decades.

Fresh analysis of Scottish government expenditure and revenue data reveals Scotland’s annual average share of UK debt interest has been £2bn a year since 1981.

The data, compiled by a pro-independence economist, has been seized upon as evidence that Scotland would be far wealthier if it no longer had to service debts amassed by Westminster.

Unionists argue the figures are misleading and do not take into account the volatile impact Scottish independence would have had on oil prices and production. Furthermore, they argue that declining oil revenues will severely impact public spending in decades to come, should Scotland win independence.

At present, Scotland contributes 8.4% towards UK