The government issued a license Wednesday enabling private lawyers to challenge the constitutionality of the CIA's targeting of alleged terrorist Anwar al-Awlaki, a U.S. citizen hiding in Yemen.

The American Civil Liberties Union and the Center for Constitutional Rights had gone to court to challenge what they say was a refusal by the Treasury's Office of Foreign Assets Control to allow the representation.

Last month, al-Awlaki was categorized as a specially designated global terrorist. Earlier this year, al-Awlaki was placed on a CIA list of alleged terrorists to be killed or captured.

The license will allow the attorneys to provide free legal services to al-Awlaki's father, Nasser, their client in the case they want to bring.

The two civil liberties groups said they appreciated the quick response by the Treasury office. They contended, however, that the office's regulations are unconstitutional because they require lawyers who are providing uncompensated legal representation to seek the government's permission before challenging the constitutionality of the government's conduct.

The groups said that they will pursue the issue and that the Office of Foreign Assets Control's attorney-licensing regulations should be invalidated.