House Democratic Leader Nancy Pelosi failed to get her colleagues Tuesday to close the House's doors for a highly unusual secret session to discuss a classified intelligence analysis on global terrorism.

The House voted 217-171 against going behind closed doors to discuss the report, which is being declassified shortly.

A closed session hasn't happened in the House since July 1983, when the chamber went into a private session to discuss the United States' support for paramilitary operations in Nicaragua.

Pelosi, D-Calif., said in a statement that a secret session is necessary to allow members to better understand the intelligence community's most recent assessment on global terrorism as part of its oversight on Iraq.

She said she hoped House Republicans would recognize the need for such an internal debate on the document, some of which leaked to the news media over the weekend.

According to the media reports, the intelligence estimate "is the administration's worst nightmare. It is not a corroboration of what the president is saying. It is a contradiction of what the president is saying," she said.

Pelosi's move followed President Bush's announcement that he will declassify the key findings of the intelligence assessment, which he and his top advisers have portrayed as a broad look at trends in terrorism rather than focusing on the impact of Iraq on U.S. national security.

Pelosi's maneuver would have required a simple majority of the House to approve.

The National Intelligence Estimate on terrorism is the most recent analysis of the nation's top intelligence analysts who work in 16 different spy agencies. Since its disclosure, the Bush administration has been rebutting suggestions that the analysis finds the U.S. is at greater risk of attack because of the Iraq invasion.

Speaking at a Washington dinner Monday night, National Intelligence Director John Negroponte said the report broadly addressed the global terrorist threat, not just the impact of Iraq. He acknowledged that U.S. analysts believe "the Iraq jihad is shaping a new generation of terrorist leaders and operatives."

But he said the war in Iraq remains important to the outcome. "Should jihadists leaving Iraq perceive themselves, and be perceived, to have failed, fewer fighters will be inspired to carry on the fight," he said.

The House has only had five closed sessions since 1812, according to the Congressional Research Service.

In the Senate, any single member can take the chamber into closed session. As a result, the chamber has held several dozen secret sessions since 1929, including one last November called by Democrats who wanted to discuss the intelligence used by President Bush in the run-up to the Iraq war.

Pelosi surprised even most of her fellow Democrats in offering the motion. She said she was not trying to use the closed session for political purposes, but rather to discuss a serious assessment that is relevant to Iraq and U.S. national security. She wants to see the administration declassify the document — without using a selective lens.

"Quite frankly, my view is that any responsible declassification will change the course of this debate on Iraq," she said.