Jack Abramoff, the disgraced former Republican super-lobbyist, has agreed a deal with US government prosecutors, opening the way for what could be the biggest political influence peddling scandal in Washington for decades.
At a brief appearance yesterday in a federal court, Mr Abramoff pleaded guilty to three sets of charges covering fraud, conspiracy to commit bribery, and tax evasion. According to his lawyers, he is also pleading guilty to two separate fraud charges connected to the purchase in 2000 of a fleet of casino gambling boats in Florida.
The convictions could send the lobbyist to jail for five years or more. But that sentence may one day prove a mere footnote to a possible corruption scandal involving as many as 20 congressmen, senators and their aides - mostly Republicans but also including some Democrats - believed to be under investigation by the Justice Department.
Under the plea bargain, Mr Abramoff is expected to tell all about his dealings with the congressmen, and the gifts lavished upon them to win their support. The favours include millions of dollars in campaign contributions, all-expenses-paid foreign trips, meals, luxury boxes at major sporting events, and generous funding of special interest groups linked to the lawmakers.
The indictment accuses Mr Abramoff of "corruptly" offering gifts and other incentives "to influence others in the performance of their official duties." Congressional ethics rules specifically bar legislators and their aides from accepting such gifts from lobbyists.
Thus far, congressmen caught up in the probe - among them the Ohio Republican Bob Ney, who went on a 2002 golfing trip to St Andrews courtesy of Mr Abramoff - have denied all wrongdoing. But the ramifications of the case extend to the heart of the ruling establishment in Washington. Mr Abramoff soared to prominence because of his ties with the younger, hard-charging generation of Republicans led by the former house speaker Newt Gingrich, who seized control of Congress in the party's stunning mid-term election victory of 1994.
One of his closest allies was Tom DeLay, who was the hugely powerful (and greatly feared) House majority leader, until he stepped down last September after being indicted for alleged illegal fundraising in his home state of Texas.
Mr DeLay, a vital congressional "enforcer" for President Bush and his legislative agenda, was himself a guest on an Abramoff-organised golf junket to Scotland in 2000. The trip was partly paid for by donations from various Indian tribes who had hired the lobbyist to protect their lucrative casino gambling operations.
Mr Abramoff also arranged at least $1m (£570,000) of financing for a conservative pressure group, the US Family Network, closely linked to Mr DeLay.
The lobbyist's downfall began with a senate committee investigation which revealed that, in conjunction with his partner Michael Scanlon, he had charged the tribes more than $80m for their services - a colossal sum even by the standards of the $4bn-a-year Washington lobbying industry. According to prosecutors, Mr Abramoff reaped roughly $20m in hidden profits from the scheme.
Pressure had mounted on Mr Abramoff when Mr Scanlon - a one-time press spokesman for Mr DeLay - agreed a plea deal of his own, admitting he conspired to bribe a member of Congress and other public officials. By his own claim, all but penniless and facing a stiff jail term, Mr Abramoff has evidently concluded that his best hope of leniency lies in testifying against those who benefited from him.
The damage - and the trepidation - however stretches far beyond Capitol Hill, into government and the White House. Last September, David Safavian, a top official in the White House budget office, resigned after being indicted for lying and obstructing the federal investigation into Mr Abramoff.
It also separately emerged that in 2003 Mr Abramoff sought $9m from President Omar Bongo of Gabon to arrange a meeting with President Bush. The two did meet the following year - though there has been no evidence it was thanks to Mr Abramoff.
Questioned by reporters yesterday, Scott McClellan, the White House spokesman, could not say whether the President had ever met the lobbyist. But he described Mr Abramoff's alleged misdeeds as "outrageous and unacceptable". If laws were broken he must be held accountable, Mr McClellan said.
The Florida charges appear unrelated to the corruption inquiry in Washington. Mr Abramoff was due to face trial in Miami next week on charges relating to the $150m purchase of the SunCruz casino cruise company. His co-defendant in Florida agreed last month to plead guilty to conspiracy and wire fraud and to testify against Mr Abramoff.
The pair are accused of faking a $23m wire transfer to make it seem they were committing their own money to the transaction. On that false understanding, two investment companies provided much of the rest of the financing. Konstantinos "Gus" Boulis, the seller of SunCruz, was later murdered, apparently in a Mafia feud.