U.S. District Judge Vaughn Walker will hold a hearing on the Justice Department's bid for dismissal of the suits under a recent law giving the telephone companies retroactive immunity from being sued.
The immunity measure was passed by Congress in July as an amendment to the Foreign Intelligence Surveillance Act, or FISA.
Government lawyers have argued that dismissal of the lawsuits is clearly required by the law and is "vital to the public interest."
But lawyers for citizens who filed the lawsuits contend the FISA amendment is unconstitutional because it "exclude(s) the judiciary from considering the constitutional claims of millions of Americans."
The lawsuits charge the telephone companies broke laws and violated constitutional rights by giving the National Security Agency information about Americans' telephone calls and e-mails without a search warrant.
The three dozen cases were filed in federal courts around the country beginning in 2006 and were consolidated before Walker in San Francisco for purposes of judicial efficiency.
Today's hearing may be lengthy. Late on Monday, Walker issued a list of 11 questions he wants lawyers to address in their arguments.
One question is how national security is harmed if the companies' cooperation with the government is publicly discussed in court, given the extensive information about the cooperation that is already publicly known and acknowledged by the government.
The judge is likely to take the government's motion under submission and issue a written ruling later.