A civil rights group on Monday asked a judge to stop city police from routinely videotaping political demonstrations as part of efforts to fight terrorism.

The New York Civil Liberties Union filed the legal challenge in Manhattan federal court. NYCLU attorney Arthur Eisenberg said the videotaping "has a wide impact on the common citizen exercising fundamental constitutional rights."

The surveillance was noted by participants in protests during the 2004 Republican National Convention, especially those who wanted to exercise their First Amendment rights anonymously, Eisenberg said.

The city's law office was evaluating the legal papers, special counsel Gail Donoghue said, but she was not prepared to comment further.

The court papers said the police department adopted a regulation in September 2004 claiming it may photograph and videotape all political activity in the city without restriction.

The NYCLU filed the legal challenge with a judge who oversees a consent decree that established surveillance guidelines. The decree settled a 1971 lawsuit alleging that police engaged in widespread surveillance of legitimate political activity and distributed the information elsewhere, including to law enforcement groups.

The NYCLU said in the court papers that the Police Department now uses an exception contained in those guidelines to fight terrorism "to wipe out the rules limiting NYPD investigation of political activity."

The exception "for the purpose of detecting or preventing terrorist activities" permits police officers to visit any place and attend any event that is open to the public on the same terms and conditions as members of the public generally.

The police department has used the exception to videotape peaceful political gatherings and to retain all the videotapes indefinitely, the NYCLU said.