The former White House intern, 24, is being investigated for committing perjury over an alleged affair that she conducted with President Bill Clinton. The change of horses in midstream is a further sign that the case against her is heading towards the court room.
William Ginsburg, a friend of the Lewinsky family, had represented her since the scandal erupted earlier this year. But he had come under frequent attack by critics, notably for what was regarded as a publicity-seeking manner mixed with a naivety about the media.
Most recently he had courted disaster by seeming to admit, in an article in a legal magazine, that his client had indeed had an affair with the President.
Ms Lewinksy's spokeswoman said last night that the two had split by mutual agreement, and that Mr Ginsburg would go back to his Los Angeles law practice.
He will be succeeded by two veteran Washington lawyers, Plato Cacheris and Jacob Stein. Mr Cacheris earned a place in the history books by defending Fawn Hall, the glamorous assistant to Reagan aide Oliver North, in the Iran Contra affair. Mr Stein was the independent prosecutor who investigated former Reagan administration attorney-general Edwin Meese, accused of corruption.
The case against Ms Lewinsky has been slowly accumulating ever since the independent counsel, Kenneth Starr, first shifted his attention from the Whitewater affair to the sexual shenanigans that are said to have gone on in the White House.
Ms Lewinsky's former friend and colleague, Linda Tripp, claimed to have tape recorded Ms Lewinsky admitting that she had an affair with the President, and lied about it in a sexual harassment case brought against the President by Paula Jones.
The aim of the prosecutor is ultimately to probe whether or not Mr Clinton and senior White House advisers conspired to make Ms Lewinsky commit perjury.
Mr Starr has refused to give Ms Lewinsky immunity against prosecution, and last week she was asked to produce handwriting and fingerprint specimens to the FBI.
This was widely thought to be a preliminary to bringing her before the grand jury in Washington. Evidently, she and her family have decided that if that is going to happen, they need more heavyweight assistance than the unfortunate Mr Ginsburg could provide.
Mr Starr is carrying out a game of legal ping-pong with the White House over the testimony of two White House advisors, Bruce Lindsey and Sidney Blumenthal.
The White House claimed that conversations with them were covered by executive privilege, but a US judge ruled against it.
The White House threatened to appeal, but Mr Starr circumvented it, asking the Supreme Court to rule on the issue; the White House withdrew its appeal.
But yesterday Mr Starr said he still wanted the court to consider the case, since the White House continues to claim attorney-client privilege for Mr Clinton's dealings with Mr Lindsey.
He has also asked the court to consider whether or not Secret Service employees can be asked to testify in the case.
Everything points to a rapid acceleration of the case over the next few weeks. Stung by criticism that the investigation was lagging, Mr Starr has now stepped up the pressure on Mr Clinton and Ms Lewinsky.