By Verna Gates
BIRMINGHAM, Alabama (Reuters) - Lawyers for the Obama administration asked a federal judge Wednesday to temporarily block Alabama's immigration law, widely seen as the toughest state measure on illegal immigration in the country.
The law, set to take effect on September 1, requires police to detain people they suspect of being in the United States illegally if a person cannot produce proper documentation when stopped for any reason.
The law will also make it a crime to knowingly transport or harbor an illegal immigrant, and requires public schools to determine, by reviewing birth certificates or sworn affidavits, the legal residency status of students upon enrollment.
The administration argues that the U.S. Constitution bars states from adopting immigration measures that conflict with federal laws. There are an estimated 11 million illegal immigrants in the United States.
"It is important that the country speak with one voice and that voice belongs to the executive branch and the Department of Homeland Security," said Deputy Assistant U.S. Attorney General William Orrick.
Georgia, Utah and Indiana are also defending new immigration laws in federal court. The Obama administration successfully sued to block Arizona's tough law last year and courts have put the laws in Georgia, Utah and Indiana on hold.
Celia Wang, attorney for the ACLU Immigrant Rights Project, said the laws grant state and local authorities far-reaching rights to "find, detain, punish and expel" people suspected of being illegal immigrants.
Conservatives have complained the Obama administration has failed to sufficiently stem the flow of illegal immigrants into the country. Attempts to overhaul federal immigration policy have gone nowhere in the U.S. Congress.
Bill sponsor, Alabama State Senator Scott Beason, a Republican, said the federal government declined to help the state with its burgeoning illegal immigrant population, forcing action.
"We asked for help but the federal government is not doing anything about it. They are not following what their laws say," he said.
(Editing by Xavier Briand)