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.
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Other entries in the UKTV channel Gold competition included jokes about Donald Trump, Brexit, Southern Rail and Ryanair UKTV channel Gold.
Temperatures will remain close to freezing.
The prime minister's announcement came as international leaders gather in Paris on the second anniversary of the climate change plan.