Analysis has been prepared by Treasury civil servants and their analysis shows that the current arrangements of a full monetary, fiscal, political union bring economic benefits to all parts of the United Kingdom.
Breaking up that union would represent a fundamental change and confront an independent Scottish state with difficult choices about what to put in its place.
More top news
Mixed fortunes across the UK tomorrow. Still breezy across the north.
The Labour leader said socialist politics would not be put "back in a box" as he appeared on stage at the festival.
There are reports that at least some MPs and Lords have been left unable to access their emails as a result of the attack.