AAP, with a staff reporter
Scotland may have to reapply for membership of international organisations such as the United Nations (UN) and European Union (EU) if it votes for independence, according to legal advice published by the British government.
In a legal opinion commissioned by London, two experts said the rest of the United Kingdom (UK) would be a "continuing state" with the same status it currently has in international law if Scotland secedes after a 2014 referendum.
But Scotland would become a "new state" and therefore would not automatically be party to thousands of treaties and membership of bodies also including NATO, the IMF and World Bank, the legal opinion said.
British Prime Minister David Cameron's office said it was taking the "the unusual step of publishing, in full" the 57-page document to clear up uncertainty about the legal status of an independent Scotland.
"If Scotland became independent, only the "remainder of the UK" would automatically continue to exercise the same rights, obligations and powers under international law as the UK currently does, and would not have to renegotiate existing treaties or reapply for membership of international organisations," Downing Street said in a statement accompanying the legal opinion.
The opinion, by professors James Crawford of Cambridge University and Alan Boyle of Edinburgh University gives four reasons for its conclusion.
Firstly, the majority of cases in recent history worked on similar principles, such as Britain and Ireland in 1922, India in 1947, Singapore and Malaysia in 1965, Bangladesh and Pakistan in 1971, the Soviet Union in 1990 and Sudan and South Sudan in 2011.
Secondly, a majority of population and territory has been an important deciding factor in such cases, and the "continuing" UK would have a majority of both population (92 per cent) and territory (68 per cent).
Thirdly Britain's "prominent role in the international order" - as one of only five permanent United Nations Security Council members, a NATO member, a nuclear weapons state under the Non-Proliferation Treaty and member of the European Union - meant any change to its status would "cause huge disruption".
Finally, the British government has already ruled out agreeing to become a "new state" as well.
However, Scotland should keep the pound if it votes to leave the United Kingdom.
Retaining the British currency "immediately" after a vote for independence could also benefit the remainder of the UK, the report concludes.
"In our view it would be in Scotland's interests to retain sterling immediately post-independence," the report says, according to extracts.
"It is also the case that, post-independence, this would benefit the rest of the UK to maintain a key trading partner.
"As nearly 10 per cent of the existing UK economy, Scotland would remain one of the largest trading partners of the UK economy."