But the Republican Chairman of the Senate Intelligence Committee, Pat Roberts, still succeeded Friday in blocking a full-fledged congressional investigation into the brewing controversy that could prove to be damaging to Republicans in the 2004 election campaign.

In fact, the chairman and the ranking committee Democrat, Senator Jay Rockefeller, appeared to disagree even on what to call their joint work, with Roberts pointedly referring to it as a "review" and Rockefeller using the word "inquiry."

But a brief joint statement issued by the lawmakers made clear the probe would go far beyond a mere review of documents from the CIA and other US intelligence agencies that was initially envisaged by Roberts.

Under the accord, the committee would examine among other things "the quantity and quality" of US intelligence on Iraqi weapons of mass destruction programs -- and "the objectivity, reasonableness, independence, and accuracy of the judgments reached by the intelligence community."

The lawmakers will also try to find out whether those conclusions "were properly disseminated to policy makers in the executive branch and Congress" and "whether any influence was brought to bear on anyone to shape their analysis to support policy objectives," the statement said.

The US-led invasion of Iraq was launched last March after President George W. Bush insisted that Iraqi chemical, biological and nuclear weapons programs represented an imminent threat.

US Secretary of State Colin Powell told the UN Security Council in February that Iraq had failed to account for hundreds of tonnes of chemical and biological agents.

But nearly six weeks after the fall of Baghdad, the US military and Central Intelligence Agency have failed to discover so much as an ounce of the banned weapons, prompting speculation that in making its case for the war and getting Congress to authorize it, the Bush administration had either used intelligence selectively, or pressured the intelligence community into turning a blind eye on questionable sources.

Critics cite a September 2002 Defense Intelligence Agency report, in which the DIA stated that there was "no reliable information" that Iraq was producing chemical weapons.

They insist the secret assessment was issued as Defense Secretary Donald Rumsfeld was telling Congress of Iraq's efforts to build up its chemical arsenal.

Vice President Richard Cheney, an ardent advocate of the war, paid repeated visits to CIA headquarters in the run-up to the conflict, a fact that made some wonder whether such attention put implicit pressure on agency analysts.

"The committee will use whatever tools of oversight it deems necessary to complete its work, including, but not limited to, document review and requests, interviews, closed and open hearings, as appropriate, and preparation of findings and recommendations," Roberts and Rockefeller said in the statement.

But the agreement falls far short of a full-fledged congressional investigation, which traditionally involves a special panel armed with subpoena power and a staff of professional investigators, widely-publicized open hearings and a voluminous report at the end of the process.

Democratic Senator Dianne Feinstein said she still favored a full probe because lawmakers needed to know if there was an intelligence failure in the lead-up to the war.

"A substantial number of senators decided to vote to authorize use of force, including myself, because of the arguments that were put forward by the administration about the intelligence that was presented to us," Feinstein said.

The House Intelligence Committee is conducting parallel hearings into the matter.

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