Scotland's Finance Secretary John Swinney has written to the Treasury's top civil servant following a row over information released by the UK Government department on the costs of independence.
The Scottish Government says figures quoted by the Treasury in a presentation on the financial implications of a Yes vote are based on "blatantly flawed and false information".
Mr Swinney has written to the department's Permanent Secretary Sir Nicholas MacPherson calling for an "urgent investigation" into the matter.
His complaint comes ahead of the publication of the Treasury's latest analysis on the costs of independence over a 20-year period from 2016 to 2035/36.
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