A U.S. court of appeals in . Washington, D.C. has decided to hear oral arguments on May 4 . in a lawsuit that challenges President Barack Obama's executive actions on immigration. A lower-court federal judge threw out the case in December, brought by Maricopa County, Arizona Sheriff Joe Arpaio. His lawyer, conservative firebrand Larry Klayman, told reporters outside the courtroom after he pleaded his case that 'we have serious issues of constitutionality involved.' Arpaio claims the White House's plan to mainstream more than 5 million illegal immigrants is clearly unconstitutional. Lawsuit: Maricopa County, Arizona Sheriff Joe Arpaio has a date with a federal appeals court, which will re-hear his legal challenge against President Barack Obama's controversial immigration executive actions . Larry Klayman of the conservative nonprofit Freedom Watch represents Arpaio's sheriff's office, and wants an injunction to stop Obama from granting legal status to millions of illegal immigrants . Obama plans to give them Social Security numbers, residency cards and work permits, even though they snuck into the United States illegally. The lawsuit argues that the policy changes, made without approval from the Republican-dominated Congress, amount to an amnesty and will encourage more people to cross the border. Last month a Texas judge ordered the Obama administration to halt its implementation of the plan, saying it would be impossible to roll back the action if a higher court ruled that it violates the U.S. Constitution. Last week, the Department of Justice requested an emergency stay to put that decision on hold so the Homeland Security Department could move ahead. Arpaio, a colorful and polarizing figure, is known for his 'tent city' jail where inmates brave the elements are are forced to wear pink underwear and clothing. Some of his deputies also use pink handcuffs while on duty in the jails. He has employed 'chain gangs' to force inmates to work outside his facilities. And he once put inmates on a bread and water diet for desecrating an American flag. Arpaio also famously claimed in 2012 that President Obama's birth certificate was 'fraudulent.' The administration has been busily fending off a handful of legal actions . designed to stop it from guaranteeing that millions of illegal immigrants could live in the U.S. with a guarantee that they won't be deported. Arpaio's suit is the first to reach the level of a federal appeals court, the final step before a possible Supreme Court review. Beryl Howell, the U.S. District Court judge who tossed his legal action late last year, was nominated to the federal bench by Obama in 2010. She ruled that the sheriff lacked legal standing to challenge Obama's immigration program, and it should be tackled in Congress. But Klayman, the attorney, had argued that the president's plan would burden U.S. law enforcement as more illegal immigrants enter the country and commit crimes. 'It's not policy,' Klayman said in December. 'He's creating law and he cannot do that under the U.S. Constitution.' Inspired by Sheriff Joe Arpaio, other law enforcement agencies are now forcing inmates to wear pink; these jailed men are in Grovetown, Georgia . This week Republicans in the House and Senate failed in a bid to tie Homeland Security funding to an order prohibiting the government from spending any money implementing Obama's immigration vision. Arpaio has suffered stinging political defeats in his attempts to slow the flow of illegal immigrants into his Arizona county. Maricopa County has already disbanded its squad of deputies that has raided businesses, arresting more than 700 immigrants who were charged with using fake or stolen IDs to get jobs. On December 17 Arpaio threw in the towel on the effort, which won him popularity among voters but was gradually dismantled by the Obama administration and the courts.
Court of appeals in Washington, DC will hear the case in May, the last stop on a journey that may end in the Supreme Court . Maricopa County, Arizona Sheriff Joe Arpaio is challenging Obama's plan to guarantee that millions of illegal immigrants won't be deported . He sued, claiming the 'amnesty' arrangement would result in more border-crossers and more crime . Circuit court judge who threw out the lawsuit in December in an Obama appointee .