The business leader, who runs Macdonald Estates, criticised Treasury Secretary Danny Alexander, Bank of England chief Mervyn King and "the Tory-led No Campaign of Darling, Davidson, Rennie and Lamont". He said that while they warned of tax rises under independence, David Cameron made Tory benefit cuts his focus.
Mr Macdonald said in a letter to The Herald today: "The scaremongering of Alexander, Darling and others and the entrenchment of the No campaign's philosophy that we must remain dependent are irrelevant to the fundamental issue of where Scotland is and can be in the world."
He added that UK debt, low investor confidence and problems in Europe left Scotland no alternative: "We have to seek, establish and insist on a new self- propelled way forward that sees us take responsibility for all of our own affairs.
"It is time that adult Scots stepped up to the plate and sought to preserve in difficult times a better country for future generations."
He argues that whether Scotland remains "dependent" on a part of the fiscal, financial or foreign policy regime of the Bank of England, Europe or the rest of the UK lies in our hands.
Meanwhile, the Yes campaign has appointed two non-SNP members to key posts. Former TV boss Blair Jenkins is chief executive and ex-MSP Dennis Canavan will chair the Yes Scotland Advisory Board.