Scotland would face an "enormous challenge" to produce their own currency if it became independent, according to the chair of HSBC, Douglas Flint.
He said: "Scotland would be faced with monetary policy implementation without representation - a very odd form of independence."
The three main parties at Westminster have all ruled out the Scottish Government's preferred option of a formal currency union between an independent Scotland and the rest of the UK.
The Scottish referendum vote will take place on September 18.
More top news
The boxer said it was the "least he could do" and even donated the £30,000 shorts he wore in his last fight against Devon Alexander.
By Sunday it should become drier with spells of winter sunshine but temperatures will still remain on the cool side.
There was no White Christmas but here's a look at the best Boxing Day snow scenes.