Scotland's economy would be in a "parlous state" if it becomes independent in next month's referendum, the chair of HSBC Scotland claims.
Douglas Flint, who describes himself as an exiled Scot, warned that sterling currency was an "anchor of stability" for Scotland.
Writing in the Daily Telegraph, he said: "At the extreme, uncertainty over Scotland's currency arrangements could prompt capital flight from the country, leaving its financial system in a parlous state."
After several Muslim organisations reported having their accounts closed by HSBC, the bank has strongly denied claims that it has made decisions related to "race or religion".
We do not discuss relationships we may or may not have with a customer, nor confirm whether an individual or business is, or has been a customer.
In general terms, decisions to end a customer relationship are not taken lightly, but are absolutely not based on the race or religion of a customer.
Discrimination against customers on grounds of race or religion is immoral, unacceptable and illegal, and HSBC has comprehensive rules and policies in place to ensure race or religion are never factors in the decisions we make.
A prominent Muslim activist has spoken of his anger after he was told that his bank account is to be closed by HSBC.
Anas Altikriti, chief executive of the think tank the Cordoba Foundation, said he had met with a "wall of silence" from HSBC over its decision to close his account and those of his wife and two sons aged 16 and 12 years old.
The Cordoba Foundation, along with Finsbury Park Mosque in north London and the Ummah Welfare Trust (UWT) have also been told their accounts are to be closed by the bank.
Mr Altikriti, 45, who was born in Baghdad and came to Britain as a young child, said he opened an account with the Midland Bank - now part of HSBC - as a teenager with just a £10 note nearly 30 years ago.
"I am angered because of the wall of silence and the tone of the letter. It is difficult to take as I regard myself as a law abiding citizen who tries to make things better in conflicts around the world and tries to promote peace and dialogue," he said.