The UK Government will today reveal the advice it has been given on what would happen if Scotland became independent from the rest of the UK.
According to Professors James Crawford and Alan Boyle, who set out their opinions in the paper, Scotland would be treated as a new country, having to renegotiate its relationship with world bodies.
The Scottish Government issued a paper last week, which assuming a Yes vote occurred in autumn 2014, could see negotiations between Scottish ministers and the UK Government, EU and international organisations concluded by March 2016.
Today's publication does not include specific advice from the European Commission on the implications of Scottish independence in the EU.
David Cameron has launched a defence of the United Kingdom as his government prepares to put the "facts" about Scottish independence to the public.
While people in Scotland will make the decision in autumn next year, the implications will have obvious impacts across England, Wales and Northern Ireland, the Conservative leader said.
"Britain is admired around the world as a source of prosperity, power and security," he said.
"Those glorious Olympics last summer reminded us just what we were capable of when we pull together: Scottish, English, Welsh, Northern Irish, all in the same boat - sometimes literally.
"If you told many people watching those Olympics around the world that we were going to erect barriers between our people, they'd probably be baffled. Put simply: Britain works. Britain works well. Why break it?"
Cameron spoke out one day before the government publishes the first in a series of analysis papers about Scotland's role in the union.
The SNP say the paper puts pressure on the UK Government to open talks about the transition process before the vote in 2014.
"Today's paper provides the people of Scotland with a clear road map as to how Scotland would make the journey from a devolved system of government with the levers of power retained at Westminster, to a nation in which the powers of our national Parliament are complete and in which the people are sovereign."