The latest victim of apparent retaliation is Bunnatine H. "Bunny" Greenhouse, the senior contracting officer for the Army Corps of Engineers, who objected -- first, internally, then publicly -- to a multi-billion dollar, no-bid contract with the Halliburton company for work in Iraq.

Lt. Gen. Carl A. Strock, commander of the Army Corps, told Greenhouse she was being removed from the senior executive service, the top rank of civilian government employees, because of poor performance reviews.

But Greenhouse's attorney, Michael D. Kohn, has appealed the decision in a letter to Defence Secretary Donald H. Rumsfeld, saying the performance review cited by Strock to justify his action "was conducted by the very subjects" of Greenhouse's allegations.

Greenhouse went public with her concerns over the volume of Iraq-related work given to Halliburton by the Corps without competition. Previously, her complaints within the agency having been ignored, she started giving interviews to national news media, and testified before a Democrat-sponsored Capitol Hill event on contracting in Iraq.

"I can unequivocally state that the abuse related to contracts awarded to (Halliburton subsidiary) KBR represents the most blatant and improper abuse I have witnessed" in 20 years working on government contracts, Greenhouse said at the Democratic forum.

Greenhouse, the Army Corps' top procurement official since 1997, has developed a reputation among those in both government and industry as being a stickler for the rules.

That has led her critics to characterise her as a rule-bound bureaucrat. But supporters see her as a defender of the public trust.

In the run-up to the invasion of Iraq in 2003, KBR had been hired to design a program to extinguish the oil fires the Pentagon believed retreating Iraqi troops would set when the invasion took place.

The government's request for proposals to implement the KBR plan stipulated that contractors had to have knowledge of KBR's plan. Consequently, KBR was the only bidder deemed eligible. The company was then hired to implement the program in a five-year, no-bid contract.

Government contacting rules generally forbid contractors hired to prepare plans and budget estimates from bidding for the work that grows out of these plans.

Government contractors who spoke with IPS on condition of anonymity said "contracts officers who insist on dotting every 'i' and crossing every 't' can drive you crazy and delay your start-date".

But all agreed that contracting regulations "are there for a purpose -- to protect the taxpayers' money. In the end, you just accept delays as a cost of doing business."

Greenhouse is only the latest in a lengthening string of whistleblowers whose cases have been rejected by the government.

Most prominent is Sibel Edmonds, who is waiting for the Supreme Court to review her charges that the behaviour of some of her fellow employees at the Federal Bureau of Investigation (FBI) compromised national security.

Lower courts turned down her case when the FBI claimed the "state secrets" privilege, contending that disclosure of Edmonds' evidence would reveal classified information.

Edmonds, a contract linguist for the bureau, was the subject of an investigation by the Department of Justice inspector general, who found that her charges were the major reason for her dismissal.

She organised and now leads the National Security Whistleblowers Coalition, which includes more than 50 former employees of national security agencies. The group has called on congress to permit whistleblowers to sue government retaliators in their personal and official capacities and to bring suit against agencies for failure to rectify misdeeds by employees or provide sufficient safeguards against whistleblower retaliation.

The government is increasingly using the "state secrets" privilege to block whistleblowers' suits. The State Secrets Privilege gives the federal government the ability to dismiss legal cases it claims would threaten foreign policy, military intelligence or national security.

It was used in 2002 in the case of Notra Trulock, who launched a defamation suit against Wen Ho Lee, a Taiwanese American computer scientist charged with stealing nuclear secrets for China from the Los Alamos National Laboratory in New Mexico. Pres. George W. Bush said national security would be compromised if Trulock were allowed to seek damages from Lee.

Lee -- who had been imprisoned for 278 days in solitary confinement -- eventually pled guilty to improper handling of classified data and was cleared of all charges relating to espionage.

The government again invoked the privilege when Maher Arar, a Canadian citizen, sought to sue then Attorney-General John Ashcroft for his role in taking Arar from New York's John F. Kennedy International Airport to Syria against his will.

He says he was first held incommunicado by U.S. immigration authorities, and eventually "rendered" to Syria, where he was imprisoned for close to a year and claims he was tortured. He was released without charges.

Former Deputy Attorney-General James B. Comey said in legal papers filed at the time that "Litigating [the] plaintiff's complaint would necessitate disclosure of classified information." The Arar case is currently being appealed to the U.S. Supreme Court.

Barbara Olshansky, the assistant legal director of the Centre for Constitutional Rights, which is representing Arar, told IPS, that government lawyers "think they can do anything they want in the name of the global war on terrorism."

Again, in August 2005, a federal appeals court affirmed the dismissal of a racial discrimination lawsuit against the Central Intelligence Agency (CIA) based on the state secrets privilege.

Jeffrey Sterling, a CIA operations officer, claimed he was told he was "too big and black" to receive certain CIA assignments, and that CIA management placed expectations on him "far above those required of non-African-American Operations Officers." He also contended he was retaliated against for using the CIA's internal equal employment opportunity process.

The court ruled that Sterling cold not prove employment discrimination without exposing classified details of his covert employment.