The Scottish Government's economic plan for independence does not add up, even taking into account oil and gas revenues, the Confederation of British Industry (CBI) warned on Wednesday.
In an analysis, the industry lobby said there was "no credible plan for deficit reduction, no clarity over what currency it will use or its future relationship with European Union."
Scotland's net deficit is larger than the rest of Britain, with 8.3 percent accounted for its GDP or 2,303 pounds (3,807 U.S. dollars) per person, according to data compiled by CBI.
It said the best way to deliver jobs and prosperity to the people of Scotland would be for it to remain part of Britain.
The Scottish first minister Alex Salmond launched his government's independence blueprint, or white paper entitled Scotland's Future, in November.
John Cridland, director-general of CBI, said: "The economic plan outlined in the white paper ignores the need for deficit reduction, instead promising more unfunded spending. On the key issues are critical to jobs and growth, the pater's lack of clarity runs the risks of jeopardizing and independent Scotland's future success."
"Independence would force Scotland's major industries to grapple with two lots of red tape and lead to Scots facing higher borrowing costs on loans, mortgage and credit cards. Keeping the pound is the best option for Scotland but that is only on offer through maintaining the union," said Cridland.
Currently, Scotland does most of its trade with the rest of Britain, which is 18 billion pounds (29.7 billion U.S. dollars) more than with any other part of the world, said CBI. Breaking up the internal market would increase costs for businesses and consumers on both sides of the border, it warned.
CBI members employ around 500,000 people in Scotland, which is approximately 13 percent of the voting population, it said.
Earlier this week, BlackRock Inc, one of the the biggest fund management companies of the world, also warned that Scotland's independence would bring major uncertainties, costs and risks.
"The white paper rightly identifies that full European Union membership is in Scotland's best interests, but an independent Scotland would have to renegotiate membership, which is unlikely to be either a smooth or quick process with new terms potentially leaving it worse off," added CBI.
Scotland's independent referendum will be held on Sept. 18.