Rangers FC chairman Sir David Murray has accused Scottish National Party leader Alex Salmond of "intimidating" Scotland's business community.
David Murray (left) said independence could harm Scotland
Mr Murray said the Nationalist leader had tried to force business into staying silent on independence.
The tycoon said "time was running out" for captains of industry to stand up for the Union before May's election.
But Mr Salmond said many high profile businessmen were positive about a move towards independence.
According to Mr Murray, in an interview with The Sunday Times newspaper, independence would lead to greater taxes.
He said: "Salmond seems to be trying to intimidate business. I hope individual businesses do come out.
"Business people opposed to independence need to be vocal."
He added: "The Union has served us well. Whether you like it or not, we have benefited from it.
"Why should we jeopardise it? There is no doubt in my mind that the majority of my staff would be taxed more in a separate Scotland.
"What you cannot have is the business community waking up in May saying they did not realise. That would be too late."
Mr Murray warned that independence could even lead to anti-Scottish sentiment among business chiefs in the City of London.
The businessman also said that he had argued with his friend Sir Sean Connery, a staunch SNP supporter, about the issue of independence.
But Mr Salmond said he was "very relaxed" about the remarks and pointed to the support of business leaders such as Crawford Beveridge, vice president of American computer firm Sun Microsystems, Kwik-Fit founder Sir Tom Farmer, Ben Thomson, the chief executive of investment bank Noble, and Bill Samuel, former RBS economist.
He added: "The growing numbers in the business community who are positive about the SNP and independence shows support is gathering ground significantly.
"And poll information indicating an SNP lead among AB voters, as well as every other category, points to very substantial business support."
"I'm pleased that David recognises the arguments for lower corporate tax to stimulate economic growth in Scotland. We have no plans to increase personal tax."