France's Constitutional Council ruled Tuesday that a French law concerning the mass killings of Armenians a century ago violates the country's constitution.

French President Nicolas Sarkozy, who had personally backed the law, immediately said he would ask the government to prepare a new bill taking into account the council's ruling.

The law passed by France's parliament in December makes it a crime to deny that the killings of some 1.5 million Armenians by Ottoman Turks in 1915 constituted genocide. The council ruled the law would violate freedom of expression and speech, which are guaranteed by the French constitution.

Turkey, which says there was no systematic campaign against Armenians, has strongly opposed the French law.

The head of a French Armenian organization, meanwhile, sharply criticized the ruling, saying it was the result of Turkish lobbying.

Relations between France and Turkey have suffered since the law's passage, with Turkey suspending its military and economic cooperation with France after the lower house approval of the measure in December. The French Senate gave the law the green light in late January.

George Mason University law student Matthew Long still has three months of schoolwork before graduation, but this week he and two classmates had a case before the Supreme Court.

The group of students is part of a new class dedicated to Supreme Court work at the Fairfax, Va., school. Nationwide, more than a half dozen law schools offer similar courses.

The students don't get to argue the cases. They aren't even lawyers yet. But students participating in the so-called Supreme Court clinics get to do everything else: research issues, draft briefs and consult with the lawyer actually presenting the case to the high court.

"We're all very much aware that you can go your entire legal career without ever being on a case before this court, and it's unbelievable that we'd have this experience as law students," Long, 26, said as he stood outside the Supreme Court after Monday's arguments in a case about a man in prison for murder in Colorado and time limits involved in his case.

Stanford University started the first Supreme Court clinic for students in 2004 and is still involved in the most cases. But schools with clinics now include Harvard University, Yale University, the University of Virginia and the University of Texas. In the past three years, clinics report that students have been involved in about 1 out of every 6 cases argued before the court. This week, students are participating in two of the court's cases.