Gary Cameron / Reuters Director of U.S. National Intelligence James Clapper appears before the House Intelligence Committee on "Worldwide Threats" in Washington February 4, 2014.

Republican members of Congress are complaining that U.S. intelligence agencies are refusing to brief them widely on a classified CIA report that concluded Russia hacked Democratic Party data in an effort to help Donald Trump win the presidency.

The Republicans said Director of National Intelligence James Clapper has refused their requests for full briefings of Congress’ two intelligence committees. U.S. government officials said the leaders of Congress and the chairmen of the two intelligence committees, known as the “Gang of Eight,” have been briefed on the CIA’s conclusion.

Nevertheless, Representative Devin Nunes, the California Republican who chairs the House Intelligence Committee and is a member of President-elect Trump’s transition team, as well as the Gang of Eight, has called for a briefing for his entire committee on the CIA assessment, which the Washington Post reported on last week.

“The committee is vigorously looking into reports of cyber-attacks during the election campaign, and in particular we want to clarify press reports that the CIA has a new assessment that it has not shared with us,” Nunes said.

Representative Ron Johnson, chairman of the House Homeland Security Committee, said his panel also has asked for a briefing but the CIA refused.

“It is disappointing that the CIA would provide information on this issue to the Washington Post and NBC but will not provide information to elected members of Congress,” Johnson said in a statement on Friday.

Three U.S. government sources, who all asked for anonymity to discuss classified information, told Reuters that the while the full congressional committees have not been briefed, the congressional leadership has, which is the standard procedure for briefing Congress on sensitive intelligence.

The Office of the Director of National Intelligence said in a statement that because President Barack Obama last week ordered the intelligence community to conduct a full-scale “review of foreign efforts to influence recent presidential elections – from 2008 to the present,” the agencies would not comment further until the study is completed.

BRIEFING TO FOLLOW

ODNI, which oversees all 16 U.S. intelligence agencies, said that when the review is complete, the U.S. intelligence community “stands ready to brief Congress.”

The office said it also would make the study “available to the public consistent with protecting intelligence sources and methods.”

The CIA based its conclusion about Russia hacking to influence the election not on irrefutable evidence but largely on its analysis of the fact that the Russians hacked both political parties while only publicizing information damaging to Democrats and their presidential candidate, Hillary Clinton, said a fourth U.S. official familiar with the agency’s work.The FBI, which has responsibility for counterintelligence investigations inside the United States, did not endorse the CIA’s finding because it does not meet the standards of evidence necessary to win a conviction in a U.S. court or identify individuals whose hacking violated American law, the fourth official said.”The CIA’s case would never hold up in court but it is almost impossible to reach a different conclusion than the agency did based on the selective nature of what the Russians did and did not choose to publicize,” the official said.

ODNI has not endorsed the CIA’s conclusion but does not dispute it. Two sources said there was “no daylight” between ODNI and CIA on the issue. An ODNI spokesman said the agency would not comment beyond its official statement.

The debate over Russian hacking, which three officials said has continued after Election Day and extends beyond the election to multiple U.S. government agencies, as well as to private firms and individuals, also is opening a rift between Trump and some Republican members of Congress.

The president-elect continues to dismiss the intelligence agencies’ conclusion that Russian President Vladimir Putin directed the hacking of this year’s election but Republicans such as Senate Majority Leader Mitch McConnell and Senator John McCain, chairman of the Senate Armed Services Committee, are calling for a full investigation.

On Friday, Senator Richard Burr, Republican chairman of the Senate Intelligence Committee, announced his committee will conduct a review in the new year of U.S. intelligence on Russian activities, including the classified information that led to the Obama administration’s Oct. 7 statement that Moscow was behind the hacking of U.S. political institutions.

The review also will cover Russian cyber activity more broadly, he said in a statement.

Burr said the review will include interviews of both Obama and Trump officials, “including the issuance of subpoenas if necessary to compel testimony.”

(Reporting by Mark Hosenball; Editing by John Walcott and Bill Trott)