Britain’s Financial Services Authority may soon have new power to offer immunity to corporate whistleblowers, a potent step intended to give regulators a stronger hand in policing against financial fraud.

Under current British law, would-be whistleblowers remain vulnerable to prosecution for the very market abuses they want to report. Chancellor of the Exchequer Alistair Darling recently proposed to undo that glitch by giving the FSA the same plea-bargaining power the Securities and Exchange Commission has in the United States. He was prompted by a recent rumor campaign from short-sellers, who were seeking to manipulate shares in HBOS Corp., a major bank and insurance group.