WASHINGTON -- Two civil liberties groups are in court challenging a requirement that they get a government license before mounting a legal attack on the decision to put alleged terrorist Anwar al-Awlaki on a CIA target list.

The Treasury secretary categorized al-Awlaki as a specially designated global terrorist last month. That made it illegal for lawyers to provide representation for al-Awlaki's benefit without obtaining the license.

The requirement is delaying efforts by al-Awlaki's father to retain the Center for Constitutional Rights and the American Civil Liberties Union to sue over the constitutionality of the Obama administration program that placed al-Awlaki on a list of alleged terrorists to be killed or captured.

Al-Awlaki is an American citizen and radical Muslim cleric believed to be hiding in Yemen.