Former U.S. Vice President Al Gore called on Monday for an independent investigation of President George W. Bush's secret domestic eavesdropping program, which he descried as "a threat to the very structure of our government."

"A special counsel should be immediately appointed by the attorney general to remedy the obvious conflict of interest that prevents him from investigating what many believe are serious violations of law by the president," Gore said in a speech to The American Constitution Society and The Liberty Coalition.

The spying program was "a threat to the very structure of our government" and threatened the foundation of U.S. democracy, said Gore, the Democratic candidate who lost to Bush in the 2000 presidential election.

Gore, who served as U.S. vice president during 1993-2001, accused Bush of breaking the law for not getting court approval for the National Security Agency (NSA) eavesdropping operation on international communications into and out of the United States.

"We still have much to learn about the NSA's domestic surveillance. What we do know about this pervasive wiretapping virtually compels the conclusion that the president of the United States has been breaking the law repeatedly and insistently," he said.

A law, the 1978 Foreign Intelligence Surveillance Act, makes it illegal to spy on U.S. citizens in the United States without warrants issued by a secret court.

Bush has insistently defended that his authorization of the secret program was within the law.

The New York Times reported last month that soon after the Sept. 11, 2001, terrorist attacks, Bush secretly authorized the NSA to conduct warrantless domestic eavesdropping on Americans with suspected ties with terrorist organizations.

Source: Xinhua