Scottish independence: JK Rowling speaks about Scottish independence
11 June 2014 Last updated at 13:20 BST
JK Rowling has donated £1m to the pro-union Better Together campaign.
A statement on her website said she respected both sides of the debate but that independence carried serious risks.
In 2012, during an interview with BBC arts editor Will Gompertz, Ms Rowling spoke of her reservations about an independent Scotland.
She said: "Scotland's doing great under devolution .... I would be personally quite averse to doing anything to destabilise that in the next few years."