Larry Summers, a former top economic advisor to the U.S. government, has added his voice to the numbers calling on Scottish people to vote against independence in next week's referendum.

Ex-Treasury Secretary Summers, currently a Harvard professor, but formerly director of the White House National Economic Council and Harvard president, joined figures as diverse as Nobel-prize winning economist Paul Krugman and billionaire investor George Soros in urging the Scots to vote "no" on Thursday.