The American Civil Liberties Union (ACLU) has been granted authority to challenge the Obama’s Administration’s claim that without due process it is within the military’s rights to kill or capture Americans who join al Qaeda.

The Center for Constitutional Rights (CCR) on August 5 joined the ACLU in the legal battle revolving around suspected terrorist Anwar al-Awlaki. Al-Awlaki is an American citizen rumored to be leading an al-Qaeda faction in Yemen. Authorities believe he is also linked to the shooting of 13 people at Fort Hood, Texas and the failed attempt to blow up a plane in Detroit on Christmas 2009.

The two groups believe that under the administration’s approach, American citizens could be denied rights afforded to them under the Constitution. The Treasury Department said its Office of Foreign Assets Control (OFAC) must grant special permission for al-Awlaki to be granted legal counsel by the ACLU and the Center for Constitutional Rights, because he is a designated foreign terrorist.

“The license issued by OFAC today will allow us to pursue our litigation relating to the government’s asserted authority to engage in targeted killings of American citizens without due process,” the groups said in a joint statement to Bloomberg News.

White House spokesman Robert Gibbs told The Washington Times that the United States hasn’t officially decided that Anwar al-Awlaki is aligned with a terrorist group, only that he has in videos cast his lot with al Qaeda and its extremist allies.

However, the ACLU and CCR claim in their suit that al-Awlaki was already on a CIA target list and that the government has tried to kill him using a drone aircraft.

A hearing in the trial is scheduled for October 4.