Libby resigned last week as Cheney's longtime chief of staff after he was indicted for obstructing justice, perjury and lying in the two-year probe into the leak of covert CIA operative Valerie Plame's identity.
Cheney and other top White House officials could be called to testify in any trial. Libby faces a maximum sentence of up to 30 years in prison.
Hours before his arraignment, scheduled to start at 10:30 am (1530 GMT), Libby brought in prominent criminal defence lawyer, Theodore Wells, according to court documents.
Wells, who is known for his trial work, has defended former Agriculture Secretary Michael Espy, former Labour Secretary Raymond Donovan, former Sen. Robert Torricelli and financier Michael Milken. He also brought in Washington lawyer William Jeffress, who is also known for white-collar criminal defence work.
Plame's identity was leaked to the media in July 2003 after her husband, former diplomat Joseph Wilson, accused the administration of twisting intelligence to justify the war in Iraq.
At Libby's arraignment, the federal judge handling the case, Reggie Walton, could set a schedule for the filing of motions and possibly a trial date.
Before any trial, Libby could still try to cut a deal with special counsel Patrick Fitzgerald on lesser charges, lawyers involved in the case said.
President George W. Bush's top political adviser, Karl Rove, was not indicted last Friday. Lawyers involved in the case said Rove remained under investigation and may still be charged.
Rove's attorney, Robert Luskin, would neither confirm nor deny any contacts with Fitzgerald since Libby's indictment. Fitzgerald is expected to inform Rove of his decision in coming weeks, lawyers said.
Libby's indictment was a damaging blow to the White House, which was already reeling from the mounting US death toll from the Iraq war, the bungled response to Hurricane Katrina and the withdrawal of US Supreme Court nominee Harriet Miers, under fire from Bush's conservative power base.
On the eve of the arraignment, White House national security adviser Stephen Hadley praised Libby as "a fine person" and said he would be missed.
CALLS FOR ROVE TO GO:
Fitzgerald's investigation showed both Rove and Libby spoke to reporters about Wilson's wife despite initial denials by the White House.
Democrats have called on Bush to fire Rove, and Republican Sen. Trent Lott of Mississippi has questioned whether Rove should retain his policy-making role at the White House. The White House has rebuffed calls for a staff overhaul.
The indictment showed Libby began seeking information about Wilson and his wife in late May 2003, some six weeks before Plame was identified publicly in a July 14, 2003, newspaper column by Robert Novak.
Libby played a major behind-the-scenes role in building the case for the Iraq war,
As part of his defence strategy, Libby was expected to argue any incorrect information he provided to federal investigators or the grand jury resulted from lapses in memory, rather than intentional lies, according to Libby's lawyer.