EDINBURGH (AFP) - British Finance Minister George Osborne said on Thursday there was no legal reason the rest of the United Kingdom should share the pound with an independent Scotland if it votes to break away in a referendum this year.

"There's no legal reason why the rest of the UK would need to share its currency with Scotland," Mr Osborne said in a speech.

"If Scotland walks away from the UK, it walks away from the UK pound."

First Minister Alex Salmond's Scottish National Party (SNP) has claimed an independent Scotland would have the right to retain the pound and become part of a currency union with the rest of Britain.

But in the British government's strongest intervention in the independence debate to date, Mr Osborne said the SNP had offered "nothing more than confusion, wild assertion and empty threats".

He said: "They are like the angry party to a messy divorce. But the pound isn't an asset to be divided up between two countries after a break-up as if it were a CD collection."

Mr Osborne repeatedly cited Bank of England Governor Mark Carney's comments last month that an independent Scotland would have to cede some sovereignty if it wanted currency union, or risk the problems shown by the eurozone.

Prime Minister David Cameron took a softer tone in a speech last week, urging all parts of the United Kingdom to persuade their Scottish friends and family to vote against independence in the September 18 referendum.