Justice Department lawyers say Cheney is immune to the court order on constitutional, separation-of-powers grounds.

The environmentalist Sierra Club and Judicial Watch government watchdog group sued in 2001 to find out the names and positions of members of the energy task force headed by the vice president that year.

They allege that Cheney, a former energy executive, drafted energy policy by consulting industry executives such as Enron Corp.'s Ken Lay, making them effective members of his task force while leaving environmentalists on the outside.

Cheney was chief executive of energy and construction company Halliburton Co. from 1995 to 2000. His 2001 energy task force produced a policy paper calling for more oil and gas drilling and a revived nuclear power program.

Cheney has acknowledged meeting Lay, but his lawyers say the energy task force was comprised of government officials, not corporate chieftains.

The Supreme Court will hear arguments in the case in the spring next year, with a decision due by the end of June.

Judicial Watch President Tom Fitton said the court's decision to take the case was not surprising "because the executive branch is often given deference. Cases that ought to be left out of court are given a hearing by the justices."

But, Fitton added, "We're confident in the end that the court is going to reject this unprecedented assertion of executive power and executive secrecy."

Sierra Club attorney David Bookbinder said the court's taking the case "will draw attention to the extreme positions the Bush administration has taken, essentially arguing that they are above the law."

There was no immediate reaction from Cheney's office. Over a year ago, U.S. District Court Judge Emmet Sullivan ordered the White House to either produce documents about the energy task force, or provide a detailed list of the documents it was withholding, and why.

The Bush administration appealed the order, even though the case was not completed in the lower court.

The U.S. Court of Appeals earlier this year refused to step in, saying Cheney did not have legal standing to refuse the judge's order.

The Energy Department, the Environmental Protection Agency and other agencies have turned over thousands of pages of documents in the case, but none have come from the White House.

Justice Department lawyers argued that judicial power cannot extend to ordering the executive branch to disclose details about the way the president gets advice - such as advice on energy policy.

Judicial Watch countered that Cheney's claims to immunity were laughable after a 1997 Supreme Court decision that discovery could proceed against then-President Bill Clinton in a case brought by sexual-harassment accuser Paula Jones.