After six days overseas, President Bush had not even set foot in the White House before being served an unprecedented lawsuit against his vice president.

For the first time ever, the legislative branch is suing the executive branch. The General Accounting Office, the non-partisan investigative arm of Congress, is going to federal court "against Richard B. Cheney, for access to certain records relating to the composition and activities of the National Energy Policy Development Group."

"Despite its efforts to reach a reasonable accommodation, GAO has been denied access to information it has a statutory right to obtain," the agency said in court papers. 

On Friday, the White House reacted by saying it was ready for the challenge. 

"We have been ready to fight for this important principle since last August, when the GAO first indicated they were going to file a lawsuit," said White House spokesman Scott McClellan. "We look forward to the matter being reviewed by the courts." 

The administration argues that the vice president, the only defendant named in the suit, has already turned over 70 pages of information and will send no more. The GAO originally wanted detailed minutes and records of Cheney's energy task force meetings. Now, the lawsuit says the GAO wants to know "who was present. ... whom the Vice President as Chair ... and support staff met to gather information ... the date, purpose, agenda, and location of the meetings; how the vice president ... or others determined who would be invited; and the direct and indirect costs that were incurred."

The vice president's task force met six times last year with Enron executives. Congressional Democrats smell political blood, but the standoff began last April, long before Enron collapsed. The energy giant announced it was bankrupt on Dec. 2.

More than a year ago when the president's administration was barely off the ground, House Government Reform Committee ranking member Rep. Henry Waxman, D-Calif., asked the GAO to look into whether special interests were shaping the administration' energy policy.  

The president has refused to provide more information, saying he and the vice president must protect their privacy so people will be comfortable giving them candid advice in confidence. 

"In order for me to be able to get good sound opinions, those who offer me opinions or offer the vice president opinions must know that every word they say is not gonna be put into the public record," Bush said during a Rose Garden news conference last month. 

Solicitor General Ted Olson, who supervises government appellate work and represents the government before the Supreme Court, will argue the administration's case, including the assertion that the GAO lacks authority to investigate anything other than how public money is spent.  The administration has already provided that information.

But the head of the GAO, David Walker, a Republican appointee, disagrees and has indicated that the information the White House provided was useless. Walker expressed reluctance to sue but said he had no other choice and that is what the courts are for.

Associate Attorney General Jay Stephens, head of the Justice Department's civil division, will help Olson lead the administration's fight, the White House said.

The Washington-based law firm of Sidley Austin Brown & Wood will represent GAO in the suit.

The Associated Press contributed to this report.

Carl Cameron currently serves as Fox News Channel's (FNC) Washington-based chief political correspondent. He joined FNC in 1996 as a correspondent.