Immigrant rights advocates filed a lawsuit Thursday that seeks to overturn Arizona Gov. Jan Brewer's order denying driver's licenses for young immigrants who have gotten work permits and avoided deportation under a new Obama administration policy.

The lawsuit alleges the state has in effect classified young-adult immigrants as not having permission to be in the country and asks a federal judge to declare Brewer's policy unconstitutional because it's trumped by federal law and denies licenses without valid justification.

"Arizona's creation of its own immigration classification impermissibly intrudes on the federal government's exclusive authority to regulate immigration," the lawsuit said.

The Obama administration in June took administrative steps to shield as many as 800,000 immigrants from deportation. Applicants must have been brought to the United States before they turned 16, be younger than 30, have been in the country for at least five continuous years, have graduated from a high school or GED program or have served in the military. They also were allowed to apply for a two-year renewable work permit.

Brewer has defended her Aug. 15 order on driver's licenses as necessary for ensuring that state agencies adhere to the intent of state laws denying public benefits to undocumented immigrants.