WASHINGTON (CNN) -- An extraordinary House committee hearing began considering a contempt measure against Attorney General Eric Holder on Wednesday even though President Barack Obama asserted executive privilege over documents sought by the panel investigating the botched Fast and Furious gun-running sting.
Committee chairman Rep. Darrell Issa, R-California, said the White House assertion of executive privilege "falls short" of any reason to delay the hearing.
However, the committee's top Democrat, Rep. Elijah Cummings of Maryland, accused Issa of setting an "impossible standard" for Holder by demanding documents the attorney general was legally prohibited from providing.
Issa has "no interest in resolving" the dispute with Holder, Cummings said.
Wednesday's development further heightened the drama of a high-profile showdown between Issa and Holder over the committee's demand for the Department of Justice to turn over more documents about the Fast and Furious program.
The White House move means the Department of Justice can withhold the documents from the House Oversight Committee, which was scheduled to consider a contempt measure Wednesday against Holder.
"I write now to inform you that the president has asserted executive privilege over the relevant post-February 4, 2011, documents," Deputy Attorney General James Cole wrote in a letter to Issa made public just before the committee meeting was scheduled to begin Wednesday.
"We regret that we have arrived at this point, after the many steps we have taken to address the committee's concerns and to accommodate the committee's legitimate oversight interests regarding Operation Fast and Furious," Cole's letter continued. "Although we are deeply disappointed that the committee appears intent on proceeding with a contempt vote, the department remains willing to work with the Committee to reach a mutually satisfactory resolution of the outstanding issues."
The hearing started 20 minutes late as panel members digested Cole's letter, and Issa immediately made clear he intended to hold a vote on the contempt measure.
The Bureau of Alcohol, Tobacco, Firearms and Explosives launched Operation Fast and Furious out of Arizona to track weapon purchases by Mexican drug cartels. However, it lost track of more than 1,000 firearms that the agency had allowed straw buyers to carry across the border, and two of the lost weapons turned up at the scene of the 2010 killing of U.S. Border Patrol agent Brian Terry.
Issa and other Republicans on the panel mentioned Terry's death by name in accusing Holder and the Justice Department of trying to stonewall the investigation of what happened.
"The Department of Justice has fought this investigation every step of the way," Issa said.
Rep. Jason Chaffetz, R-Utah, complained that subpoenas for documents remained unresolved eight months later.
"We have not gotten to the bottom of this, and Brian Terry was killed in December of 2010," Chaffetz said.
Cummings and other Democrats challenged the Republican contention of stonewalling by Holder, saying political motivations were at play.
"It shouldn't be a political witchhunt against the attorney general and the president in an election year," said Rep. Carolyn Maloney, D-New York.
Issa and Holder met Tuesday evening in what was billed as a final effort to resolve their differences. However, the meeting amounted to little more than a reiteration of the positions the two staked out in an exchange of letters the previous week, and Issa said afterward the committee would proceed with its contempt vote if Holder failed to turn over the documents in question.
Holder told reporters that he offered to provide the documents on the condition that Issa gave his assurance that doing so would satisfy two committee subpoenas and resolve the dispute.
"They rejected what I thought was an extraordinary offer on our part.," Holder said. Asked about whether Issa was open to resolving the issue before the committee meets Wednesday, Holder said: "I think we actually are involved more in political gamesmanship" instead of a sincere effort to get the requested documents.
In particular, Issa's committee wants documents that show why the Department of Justice decided to withdraw as inaccurate a February 2011 letter sent to Congress that said top officials had only recently learned about Fast and Furious.
In a letter to Issa after the Tuesday meeting, Cole reiterated Holder's position that the documents would show Holder had nothing to hide about his role in Fast and Furious.
Cole noted that the lone point of dispute was whether the February 4,2011 letter was part of a broader effort to obstruct a congressional investigation.
"The answer to that question is an emphatic 'no' and we have offered the Committee the opportunity to satisfy itself that that is so," Cole wrote.
A committee statement issued before Tuesday's meeting said it was a chance for Holder to meet the panel's demands for additional documents, which would allow for a postponement.
"Currently, (the Department of Justice) has not delivered or shown the committee any of the documents it has said it is prepared to produce," the statement continued. "It is not clear if they will actually produce these documents to the committee before the Wednesday vote to facilitate a postponement."
Holder, however, said he made an unprecedented offer of documents and a briefing to the committee, which so far has turned him down.
Cummings, who also attended the Tuesday meeting, said Holder was trying to end a protracted standoff with the Republican-led panel.
"He sees this as a never-ending process," Cummings said in describing Holder's concerns about the continuing requests for more documentation.
Another person in the room, Senate Judiciary Committee Chairman Pat Leahy, D-Vermont, said afterward that he supported Holder and appreciated "that he is going the extra mile to resolve this."
However, Sen. Charles Grassley of Iowa, the ranking Republican member of the Senate Judiciary Committee who also participated in the meeting, said Holder was seeking to get cleared before he actually turned over any of the requested information.
"The attorney general wants to trade a briefing and the promise of delivering some small, unspecified set of documents tomorrow for a free pass today," Grassley said afterward. "He wants to turn over only what he wants to turn over and not give us any information about what he's not turning over. That's unacceptable. I'm not going to buy a pig in a poke."
While such disputes have long been part of the interaction between Congress and the government, the public showdown between Holder and Issa -- coming in the politically charged atmosphere of an election year -- raised the stakes on an already volatile issue.
Issa has accused the attorney general of stonewalling an investigation into Fast and Furious and how the Justice Department provided Congress with erroneous information about it. The department says it already has handed over more than 7,000 pages of records to House investigators, and that the remaining material Issa wants could jeopardize criminal prosecutions.
The back-and-forth letters exchanged between Holder and Issa before Tuesday's meeting revealed an incremental negotiation over what the committee wanted and what the Department of Justice was willing to provide.
CNN's Terry Frieden, Deirdre Walsh and Ted Barrett contributed to this report.