In a speech given to the Scottish Council for Development & Industry on 29 January, Mark Carney, Governor of the Bank of England, outlined the prospect of a currency union should Scots vote for independence. In the speech, Mr Carney discussed the economic recovery, noting that it was not yet appropriate to end emergency monetary policies. He reassured businesses that interest rates would not rise immediately and when they did, they would do so in a gradual manner. Mr Carney then turned to the cost and benefits of shared currencies, noting that this was a matter for negotiation between Westminster and Holyrood and asserting thtat 'The Bank of England would implement whatever monetary arrangements were put in place'.
You can read the full text of the speech at the Bank of England website.