WASHINGTON (Reuters) - Arizona Wednesday asked the U.S. Supreme Court to hear its appeal and overturn a ruling that put on hold key parts of the state's tough law cracking down on illegal immigrants.

The law, signed by Republican Governor Jan Brewer in April 2010, requires police to check the immigration status of anyone they detained and suspected was in the country illegally.

A federal judge blocked that provision and other key parts just before the law was to take effect in July last year. A U.S. appeals court upheld that ruling, prompting the state's appeal to the Supreme Court.

Other provisions put on hold require immigrants to carry their papers at all times and ban people without proper documents from soliciting for work in public places.

"I am hopeful that the U.S. Supreme Court will choose to take this case and issue much-needed clarity for states such as Arizona that are grappling with the significant human and financial costs of illegal immigration," Brewer said in a statement.

The Obama administration had sued, challenging the law on the grounds it improperly interfered with the federal immigration system. The judge and appeals courts agreed.

About 11 million illegal immigrants are believed to be in the United States. Immigration has become a major issue in states such as Arizona that border Mexico.

Opponents of the law, including President Barack Obama, many Democrats and civil rights groups have said it would lead to harassment of Hispanic-Americans. But supporters have said the federal government has failed to do enough to stop the flow of illegal immigrants into the country.

Obama has supported a comprehensive overhaul of immigration laws, but such legislation has gone nowhere in the Congress.

Brewer announced in May the state would appeal to the Supreme Court and the 41-page appeal was filed Wednesday.

Former Bush administration attorney Paul Clement said in the appeal that the case involved "a matter of pressing importance."

"It is widely recognized that the federal immigration laws are not adequately enforced," he wrote. "This broken system leaves the people and government of Arizona to bear a disproportionate share of the burden of a national problem."

The Obama administration is expected to oppose the appeal. The Supreme Court during its upcoming term that begins in October will decide whether to hear the case.

(Reporting by James Vicini, Editing by Christopher Wilson)

Source: Reuters US Online Report Domestic News

Additional links from Reuters US Online Report Domestic News

Reuters services for news professionals

Reuters Pictures - Search, select, buy

Share your news photos and videos with Reuters and Yahoo!

Reuters Reporter Blogs

Mochila insert follows...