Members of both parties said a probe was warranted in the wake of a sworn statement by a Washington-based British journalist.

The reporter, Christopher Hitchens, said that Mr Blumenthal had described Ms Lewinsky as a "stalker" at a lunch last year shortly after news broke of her affair with Mr Clinton.

"Mr Blumenthal stated that ... the president was 'the victim' of a predatory and unstable sexually demanding young woman," Mr Hitchens said in his affidavit.

White House aide Sidney Blumenthal: Under fire

In his testimony to the Senate impeachment trial and special prosecutor Kenneth Starr's grand jury, Mr Blumenthal denied passing to the news media President Bill Clinton's assertion to aides that Ms Lewinsky made sexual demands.

Connecticut Democrat Senator Joseph Lieberman said the case should be forwarded to the Justice Department.

Texas Republican Senator Phil Gramm said: "Perjury is serious business."

However, Mr Blumenthal on Sunday again denied that he had been a source for the story. He said he spoke about Ms Lewinsky to friends - including Mr Hitchens - but "did not reveal what the president told me to any reporter".

A former friend

"Though I do not recall the luncheon with my then-friend of 15 years, Christopher Hitchens ... the notion that I was trying to plant a story with this rabid anti-Clinton friend is absurd," he said in a statement issued by his lawyer, William McDaniel.

Mr Hitchens swore in his affidavit that he knew of other journalists who had been told the same thing by Mr Blumenthal.

Clips of video testimonies from Mr Blumenthal, Ms Lewinsky and Vernon Jordan - have been broadcast around the world as part of the Senate trial.