A former GCHQ translator who leaked details of an alleged plot to bug UN delegates before the Iraq war is urging more whistle-blowers to speak out.
Katharine Gun was sacked from her job as translator in June 2003
Katharine Gun was sacked for revealing details of a memo, but a charge under the Official Secrets Act was dropped.
She has now started a campaign to encourage people who spot government wrongdoing to voice their concerns.
Her Truth-Telling Coalition, which already has about 15 members, will back whistle-blowers around the world.
The group is supported by the former US defence analyst Daniel Ellsberg, who leaked the Pentagon Papers about US involvement in Vietnam.
Ms Gun, from Cheltenham, attracted huge attention when she blew the whistle on what she believed was an American dirty tricks campaign to win UN backing for the war in Iraq.
She had seen a memo which reportedly said the US National Security Agency had begun a "surge" in eavesdropping on UN Security Council countries crucial to the vote on a second resolution for action in Iraq.
GCHQ is the home of Britain's intelligence-gathering operations
She claimed the e-mail, leaked to the Observer newspaper in January last year, was from US spies asking British officers to tap phones of nations voting on war against Iraq.
She told BBC Radio 4's Today programme the new "support group" was made up of people who knew what it was like to be thrown into the limelight as a whistle-blower.
"It is a very difficult decision to contemplate disclosure and this organisation is there to help people if they need it," she said.
"It's not a popular pastime, but there is a time when people need to disclose information, if they believe there are illegal practices going on."
Ms Gun was sacked from her job as a translator at the government's GCHQ monitoring centre in Cheltenham in June 2003.
She was then prosecuted under the Official Secrets Act but the case was withdrawn before it came to trial because the prosecution offered no evidence.
Ms Gun, the daughter of a university lecturer who grew up in Taiwan and is a fluent Mandarin speaker, always admitted leaking the e-mail.
She justified the disclosures, saying in a statement that she had "only ever followed her conscience" to prevent an "illegal war against Iraq".