Updated: 4:07 p.m.

House Oversight and Government Reform Chairman Darrell Issa (R-Calif.) invited members of both parties to review secret wiretap applications that have become a point of debate in the “Fast and Furious” gun-walking probe.

Issa and other key Republicans have asserted the wiretap applications, which were approved by senior Justice Department officials in Washington, D.C., include detailed descriptions of the tactics at the heart of the Fast and Furious scandal.

Attorney General Eric Holder and Rep. Elijah Cummings (D-Md.), ranking member on the Oversight panel, have disagreed with Issa’s characterizations and said the applications were reviewed narrowly for whether probable cause was present.

The issue is important because the Justice Department has conceded the tactics were used in Fast and Furious, a botched gun-smuggling investigation, but denied that senior Justice officials knew they were being used.

Missing from the public debate has been the wiretap applications themselves, which are under court seal. Issa obtained the documents despite the seal.

Issa plans to challenge Democrats on the Oversight panel on whether they have taken the opportunity to review them and, if they have, whether they agree with Holder and Cummings about the contents of the applications.

“Oversight Democrats who oppose contempt will be challenged on whether they have personally reviewed the contents of these wiretap applications. Those who review these documents, which were approved by senior officials, will be pressed on whether they agree the tactics described are objectionable or if they see no problems with what is described,” a GOP aide said.

The move shows confidence by Issa that his characterizations of the applications are correct and could open fissures among Democrats if some of them agree the applications should have raised red flags to the senior officials who approved them.

Justice “has denied that senior officials were provided information about the tactics used in Operation Fast and Furious. The wiretap applications obtained by the Committee show statements made by senior Department officials regarding the wiretaps to be false and misleading,” said a Friday memo with the invitation to review the applications.

The memo stipulates that only Members of Congress are allowed to review the documents and that copies of the documents may not be removed.

With a committee vote on Holder’s contempt report still scheduled for Wednesday, Rep. Peter Welch (D-Vt.) hit back at Issa, saying the investigation has “crossed a line” into becoming a “political spectacle.”

“This kind of relentless drumbeat on the Republican side to make accusations without foundation really seems to be much more political than substantive,” Welch said, adding that he planned to review the wiretap applications.

Welch noted that guns also “walked” in Operation Wide Receiver, a smaller-scale operation conducted during President George W. Bush’s administration by the same ATF office in Phoenix that conducted Fast and Furious.

“If the committee was truly interested in accountability … since this started in the Bush administration, you’d be looking to find out what happened at the origin of this,” Welch said.

Although fierce in his denunciations of GOP tactics in their investigation, Welch was less adamant when defending the Justice Department’s legal authority to withhold documents under Congressional subpoena.

“The Congress can subpoena documents and does and should have liberal access to information. I strongly support the oversight ability of Congress. And in order to exercise that, we have to have access to a substantial range of documents. On the other hand, the oversight responsibility has to be done in a responsible way where it’s not just a fishing expedition,” Welch said.

Cummings issued a staff memo last week arguing that “holding the Attorney General in contempt of Congress for protecting these documents is an extreme and blatant abuse of the Congressional contempt power that undermines the credibility of the Committee.”

However, a report by the Congressional Research Service on Congressional oversight of the DOJ offers a broad view of Congress’ legal authority to demand internal documents.

The report says that from 1920 to 2007, Congress has “consistently sought and obtained” internal DOJ documents and successfully demanded information “from the Attorney General down to subordinate personnel,” adding that court precedents have affirmed broad Congressional investigative authority in nearly every instance, regardless of whether the documents relate to ongoing criminal investigations.

On Friday, Issa said he would delay contempt proceedings if Holder produced a key category of documents.

In a letter to Issa dated Monday, Holder proposed meeting with Issa at 11 a.m. today, saying that “we expect that this extraordinary accommodation will fully address the remaining concerns that you and House Leadership have identified in your written and oral communications to the Department over the last few weeks.” Holder also requested that the meeting include Senate Judiciary Chairman Patrick Leahy and Cummings, “in keeping with the protocols of this investigation,” and cited Issa’s “inclusion” of Senate Judiciary ranking member Chuck Grassley (R-Iowa) in the meeting.