Libby faces a January trial on perjury and obstruction charges for allegedly lying to investigators about what he told reporters who were asking questions about former CIA operative Valerie Plame Wilson. Plame's identity was leaked to reporters after her husband, former ambassador Joseph Wilson, wrote an op-ed criticizing the Bush administration's pre-war intelligence on Iraq.
"We will be calling the vice president," said Libby attorney Ted Wells. Jury selection is scheduled for Jan. 8.
Cheney's office immediately released a statement in response to plans to call him as a witness.
"We've cooperated fully in this matter and will continue to do so. In fairness to the parties involved, and as we have stated previously, we are not going to comment further on a legal proceeding," said Lea A. McBride, Cheney's spokeswoman.
Special Counsel Patrick Fitzgerald told Judge Reggie Walton last week that he did not expect the government to block the testimony of Cheney or other administration officials.
"We don't expect him to resist," said defense attorney William Jeffress.
Jeffress would not say whether Cheney is under a subpoena to testify. Issuing a court order to a sitting vice president could raise separation of powers concerns, but Jeffress said it was not an issue.
Sitting presidents, including Bill Clinton and Gerald Ford, have testified in criminal cases, but presidential historians and separation of powers experts said they knew of no vice president who has done so. The first President Bush was subpoenaed to testify in the Iran-Contra trial of Oliver North. At the time, Bush was Reagan's vice president, but Bush was president by the time a judge ruled he did not need to testify.
Former New York Times reporter Judith Miller and NBC News Washington bureau chief Tim Russert are expected to be prosecution witnesses. Libby's lawyers said in court papers that several reporters will testify on Libby's behalf.
Two unidentified reporters may resist testifying, Libby's attorneys said, but they expect to resolve that issue before trial.
Libby also has sought a subpoena for the tape of Washington Post reporter Bob Woodward's interview with former Deputy Secretary of State Richard Armitage. Armitage has admitted he discussed Plame's job with Woodward in 2003 but said it was a passing, inadvertent comment.
If admitted into evidence, the tape could be played at trial. The tape has been turned over to prosecutors, and Libby's attorneys said they expect no objection to their subpoena.
Prosecutors may ask Cheney how the White House responded to Wilson's criticisms. Cheney was upset by Wilson's comments, Fitzgerald has said, and told Libby that Plame worked for the CIA.
That conversation is a key to Fitzgerald's perjury case. Libby testified that he learned about Plame's job from a reporter.
Cheney could also help prosecutors undermine Libby's defense that he was so preoccupied with national security matters, he forgot details about the less-important Plame issue. Prosecutors argue that Plame was a key concern of the vice president, and thus would have been important to Libby.
Cheney and Libby got to know each other when Cheney was defense secretary under the first President Bush. Libby has been extremely loyal to Cheney and, in return, had the vice president's unwavering trust.
By 2000, Libby was working as a top adviser to Cheney in the presidential campaign and then followed him to the White House. In the White House, he was known as "Cheney's Cheney" for being as trusted a problem solver for the vice president as Cheney was for Bush.
Even after Libby's indictment, Cheney called him "one of the finest men I've ever known."
FOX News' Ian McCaleb and The Associated Press contributed to this report.