The White House ordered its staff yesterday to "fully co-operate" with a criminal probe launched by the Justice Department to try to find out who leaked the name of a CIA staff officer to the press.
As the affair compounded the administration's post-Iraq miseries, Alberto Gonzales, the White House counsel, sent a memo to staff ordering them to preserve all material and records linked to the probe adding that Mr Bush wanted, "to get to the bottom of this".
Whoever was responsible for the leak violated a 1982 law making it a criminal offence to divulge the identity of an agent. The crime is punishable by up to 10 years in prison.
But, straight after the Justice Department had announced its investigation, Democrats contended that in-house lawyers working for John Ashcroft, the Attorney General, could not be impartial. Democrats are demanding the appointment of a special prosecutor to investigate the leak.
The CIA operative in question is the wife of Joseph Wilson, the former ambassador who, last year, was sent by the agency to Africa to probe reports that Iraq had been seeking to buy yellow cake uranium from Niger.
Mr Wilson's report cast deep doubt on that theory but, nevertheless, the Niger allegations found their way into Mr Bush's state of the union speech in January.
Last summer, Mr Wilson wrote a newspaper article about his mission, claiming its conclusions had been deliberately ignored by the administration. Then, a few days later, the veteran conservative journalist Robert Novak wrote a column naming Mr Wilson's wife as a CIA analyst specialising in weapons of mass destruction.
According to the Washington Post, White House officials contacted several other reporters, identifying her - though Mr Novak was the only one who did so in print.
The apparent motive of the leak was to smear Mr Wilson, by implying he had been put up to the mission by his wife.
Inevitably, Karl Rove, Mr Bush's senior adviser and considered to be the President's in-house dirty-tricks specialist, was at the top of the suspects' list. Though Mr Rove flatly denied the charge yesterday, Mr Wilson insisted he must at the very least have "condoned" the leak.
In Washington, mole-hunts of this sort are rarely successful but the real danger for Mr Bush would arise if members of his own Republican party were to express outrage and back Democrat calls for an outside investigation.
Already, however, memories are being rekindled of previous Washington scandals - not least Whitewater which led from modest and arcane beginnings to a presidential impeachment trial on Capitol Hill.
Certainly, the scandal has come at the worst possible time for the Bush administration, under growing fire for its management of post-war Iraq and its complete failure to find any of Saddam Hussein's supposed chemical and biological weapons.
Democrats have predictably been having a field day, interpreting the leak as further proof of the perfidy of the Bush White House. But prominent Republicans are starting to complain that the administration sold the war under false pretences.
Meanwhile, John Dean, White House counsel at the time of the 1972 Watergate break-in and a man who knows a thing or two about underhand politics, declared yesterday that this administration was employing tactics which were "worse than Nixonian." Some indeed maintain that Mr Wilson is on a Bush-era equivalent of the infamous "enemies' list" operated by the Nixon White House.
Mr Bush will at least be spared the torment of an independent counsel, such as the one that created such misery for his father in the Iran-Contra affair, and for President Clinton over Whitewater.
Last year, Congress allowed the independent counsel statute to lapse, amid a widespread belief that Kenneth Starr, the Whitewater counsel, had run amok in a post endowed with very great powers but very little accountability.
The criminal investigation into the leak is being carried out by Justice Department lawyers. If that is deemed insufficient, the Attorney General has the power to appoint a special prosecutor. But that prosecutor may also be fired by Mr Ashcroft, unlike a special counsel along the lines of Mr Starr whose mandate may only be revoked by Congress.
Joe Lieberman, one of the 10 Democratic Presidential candidates, called last night for the office of independent counsel to be reinstated. But there seems little appetite on Capitol Hill, so far at least, for such an idea.
This 1922/23 scandal was named after the government-owned oilfield at Teapot Dome, Wyoming. It led to the the conviction for bribery and conspiracy of Albert Fall, the Interior Secretary for President Warren Harding.
Arose from the 1972 break-in at the Democratic Party headquarters, and became the biggest scandal in US political history, leading to the resignation in 1974 of President Nixon, right, and the disgrace and jailing of several of his top-ranking aides.
The probe into the arms-for-hostages affair that engulfed the Reagan administration in 1986/87. It led to the conviction of Colonel Oliver North, above, and much controversy over whether vice-President George Bush was aware of the illegal activities.
The affair began with an investigation into an Arkansas land deal in 1978 by Bill and Hillary Clinton but became a catch-all investigation of the Clintons, culminating in the Monica Lewinsky scandal, for which Mr Clinton was impeached, and acquitted, in 1998.Reuse content