Democratic Senators forced the US Senate to hold a rare secret session to discuss the scandal that led to the resignation of a senior White House aide last week and the now-discredited intelligence used to justify the 2003 invasion of Iraq.
Senate Republican leaders were livid about the tactic, which drew public attention back to Iraq as President George W. Bush faced the fall-out from an indictment of a senior aide related to the handling of pre-war intelligence.
Republican Majority leader Bill Frist of Tennessee said: "Never have I been slapped in the face with such an affront to the leadership of this grand institution."
But Senate Democratic Leader Harry Reid of Nevada said what he called Republican stalling on the issue had been "a slap in the face for the American people."
Democrats invoked a little used rule to temporarily shut down television cameras in the chamber, clear galleries of reporters, tourists and other onlookers, force removal of staff members and recording devices and stop work on legislation.