During a debate with Scottish first minister Alex Salmond Darling said independence “would be ruinous to the financial services industry” as Scotland would not have the security of its own central bank.
He said: “How would RBS and Standard Life exist if there was no bank behind it?”
He added that if Scotland was reliant on the Bank of England this would undermine its independence anyway.
Darling asked Salmond whether he had a plan B to retaining the pound, with the Scottish National Party leader ruling out use of the Euro.
However, Salmond avoided questions on establishing a new currency, as he repeatedly said “keeping the pound is the best option for Scotland”.
He added an independent Scotland could utilise its oil reserves for prosperity, like Norway.
But many of those who witnessed the debate felt Salmond left many unanswered questions.
Ray Boulger, senior technical manager of John Charcol, said: “Where do we draw the line? Should the North East of England have a separate parliament?
And he added: “It would take Scotland a long time to get into the EU. Salmond said he doesn’t want the euro, but he’s got to commit to that.”
Salmond drew criticism from the Glasgow audience, as one onlooker said: “Mr Salmond, I am disappointed in you. As a politician of some note, some of your remarks have been snide and not very nice coming from the leader of the Scottish parliament.”
Cameron Penny, account manager at West End London consultancy Cicero, was troubled by Salmond’s lack of answers.
He said: “The esoteric nirvana of Alex Salmond’s Scotland is far removed from the issues of what job prospects people will have, what job prospects their children will have and what their economy’s going to be like.
“That’s the big impact for savers and people with mortgages.
“What people are concerned about first and foremost when they cast their vote is how they put a roof over their heads, food on the table and how they clothe themselves.”