Bridget Kendall: Clinton showing no emotion

The proposal went through the committee strictly on party lines with 21 Republicans in favour and 16 Democrats against.

The verdict will go before the full House of Representatives for endorsement later in the week, making Mr Clinton only the third president in American history to be subjected to the threat of formal impeachment proceedings.

Rageh Omaar: "The vote was partisan almost to a fault"

The proposed investigation will be unlimited both in time and in the scope of its questions.

Although the outcome of the vote was expected, Democrats were nevertheless indignant, accusing Republicans of being driven by narrow party concerns.

Watergate-style investigation

Republicans called for a Watergate-style investigation to find "whether sufficient grounds exist for the House of Representatives to exercise its constitutional power" to impeach the president.

The leading Republican lawyer, David Schippers, cited "substantial and credible evidence" of 15 possible grounds for impeachment - up from the 11 originally mentioned in the Starr report.

The chairman of the House Judiciary Committee, Henry Hyde, launched the landmark debate by calling for an "an honest effort to do what is best for the country".

Speaking in open session, he reminded the committee members they were not there to pass judgement on the president's conduct but to "decide whether to look further or look away".

John Conyers, the committee's leading Democrat, tried to play down the seriousness of Mr Clinton's conduct and the evidence against him.

"This is not Watergate. It is an extramarital affair," he said.

"There is no support for any suggestion that the president obstructed justice or tampered with witnesses or abused the power of his office."

Republican Bill McCollum decried Mr Conyers' stance.

"Even if it were only shown to us that the president lied under oath ... that is enough to impeach and for him to be thrown out of office," he told fellow members.

Richard Nixon: Subject of last impeachment debate

Democratic member Charles Schumer acknowledged that Mr Clinton's actions were "wrong and possibly illegal" but said "censure or rebuke and not impeachment is the right punishment."

The hearing represents only the third time an impeachment inquiry has been launched against a president.