Oral arguments are set for Monday at U.S. District Court in Detroit at which the American Civil Liberties Union will ask Judge Anna Diggs Taylor to declare the spying unconstitutional and order it halted.
The case goes to the heart of the larger national debate about whether President Bush has assumed too much power in his declared war on terrorism.
soon after the Sept. 11, 2001, terrorist attacks, allowing the NSA to monitor the international phone calls and e-mails of U.S. citizens without first obtaining warrants if in pursuit of al-Qaida suspects.
The ACLU sued the NSA on behalf of scholars, journalists and attorneys, claiming that warrantless wiretaps violate the U.S. Constitution and the Foreign Intelligence Surveillance Act of 1978, or FISA.
"The NSA has the capability of James Bamford, an NSA expert and author who is supporting the ACLU suit.," said
Department of Justice lawyers have asked the judge to dismiss the suit because it would reveal state secrets.
Regardless of how the judge rules on state secrets, the government lawyers say Congress granted Bush surveillance privileges by authorizing the use of force against al-Qaida following the Sept. 11 attacks, and that he has the inherent right to order the wiretaps under presidential war powers.
"That is a total misunderstanding of the way the separation of powers are supposed to work in our democracy," said Ann Beeson, the lead ACLU lawyer in the case.
"It is very clear that when the framers (of the Constitution) set up the three branches of government, they gave Congress the power to regulate what the president can do, even during wartime and emergencies. If they hadn't done that, we'd be back to the days of King George III," she said.
Some Republicans,, differ with the White House and maintain that the post-Sept. 11 authorization of the use of force did not alter FISA.
The committee is considering several bills that would either tighten or loosen congressional oversight of the NSA.
Specter said on Sunday that if talks with the, he would again seek to subpoena executives from telecommunications companies to testify about their possible involvement.
"If the talks aren't productive, I'm prepared to go back to the hearings, and I'm prepared to go back to the subpoenas if necessary," he said on CNN's "Late Edition." Last week, Specter backed off trying to issue subpoenas when Vice President Dick Cheney lobbied Republicans to oppose that effort.
Verizon Communications and BellSouth have they gave tens of millions of phone records to the National Security Agency. AT&T, also named in the report, has not addressed the issue.