An independent Scotland could lose the pound - that was the warning from the Chancellor George Osborne as he launched a new treasury report today.
The Scottish Government says it wants to create a currency union with the rest of the UK if Scots vote 'yes' in the referendum next year.
However, Mr Osbourne cast doubt on the idea that a deal could be struck and warned Scotland could be heading into 'unchartered waters.'
Kathryn Samson reports:
Borders MP Michael Moore has said that the currency paper published by the UK Government today "clearly shows that we are better together".
Scottish First Minister Alex Salmond, speaking to BBC News 24, accused the Chancellor of "political sabre-rattling".
He said that was for the "very simple reason that huge Scottish resources such as oil and gas would continue to protect the sterling balance of payments"
Speaking in Glasgow Chancellor George Osborne said, "the conclusion is clear, the pound we share works well. The saying goes - if it ain't broke don't fix it, but I say, if it ain't broke don't break it."
He added, "I want the best for Scotland and for all our United Kingdom. We're better together."
Speaking in Glasgow the Chancellor has said: