But Mr Salmond has been spectacularly wrong-footed by Mr Darling’s campaigning style.
“He thought Alistair would rise above the petty politics and name-calling and bring his considerable intellect to bear and provide a serious challenge to the First Minister. But he immediately sounded like a backbench Labour MP from deepest Lanarkshire. His speech in Haddington which said Scots using the pound after independence would become “serfs” left Mr Salmond grasping for a hold on reality, “ said Mr Gunn. He asked me: “Is Alistair saying we will wear sacking tabards, lose all our teeth and get rickets while gouging out a living from the barren soil?”
It is believed the transformation of Mr Darling from Big Beast at Westminster to Little Furry Animal in Scotland has dangerously weakened Mr Salmond’s confidence.
A spokesman for Better Together said: “He can hide in his bunker if he likes. Alistair is taking tap dancing lessons and learning how to sing to capitalise on his reputation as a Happening Guy. Watch how he winks at the camera in his next interview. I shouldn’t tell you this but he’s being mentored by Simon Cowell. I’ll let you know when his single is coming out. I think it’s a cover of Coward of the County.”