Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. US Government to Challenge Arizona Immigration Law VOA News 06 July 2010 Federal immigration agents stand outside Sergio's Shuttle in Phoenix, Arizona, 15 Apr 2010 Photo: AP Federal immigration agents stand outside Sergio's Shuttle in Phoenix, Arizona, 15 Apr 2010 The U.S. Justice Department has decided to file a lawsuit challenging the southwestern U.S. state of Arizona's controversial new immigration law. Sources with the justice department have told reporters the suit will argue that enforcing immigration is a federal responsibility and the Arizona law intrudes on that authority.  The Arizona law, due to take effect later this month, requires police to examine a person's immigration status if there is reasonable suspicion the person is in the country illegally. It will also make illegal immigration a state crime. The lawsuit has been expected for weeks. U.S. President Barack Obama has called the Arizona measure "misguided," and civil rights groups say the law would lead to race-based discrimination. Supporters say the Arizona measure is a valid response to the issue of illegal immigration. The supporters say the federal government has not done enough to combat the problem and that the law will help fight crime blamed on illegal immigrants. The lawsuit could be filed as early as Tuesday. Some information for this report was provided by AP. .