LIVE debate in Congress (without commentary)

Mr Livingston, who was due to take over the speaker's job from Newt Gingrich in the new year, said he was stepping down after it was revealed earlier this week he had been unfaithful in his marriage. He pledged to leave the House altogether in six months.

Mr Livingston then urged Mr Clinton to follow suit and resign his presidency.

Earlier, congressmen returned to the House of Representatives floor to wrap a tense and partisan debate.

Within the next few hours they will vote on four impeachment articles set against Mr Clinton over his handling of the Monica Lewinsky and Paula Jones affairs.

Representatives will vote separately on each article. The president is accused of:

• Perjury before a grand jury
• Perjury in the Paula Jones civil case
• Obstruction of justice
• Abuse of power

If, as seems likely, at least one of the articles is voted through, Mr Clinton will become the first American president to be impeached this century, and only the second in the history of the United States.

BBC Washington correspondent Tom Carver looks at the background to impeachment

But that will not automatically trigger Mr Clinton's removal from office. Rather he will be sent to the Senate for a full-scale trial that could last anything between a few days and several months.

In a House torn by bitter partisanship, members spent 13 hours on Friday debating the impeachment motion.

The debate went back and forth, but the underlying arguments remained the same until the session finally broke up at 2200 (0300 GMT).

While Republicans insisted Mr Clinton's actions amounted to the "high crimes and misdemeanours", the definition of impeachment, Democrats claimed a lesser punishment of censure would be more appropriate.

First Lady backing

Early on Saturday morning, the first lady, Hillary Clinton, took the unusual step of addressing Democrat members on Capitol Hill.

The move was seen as a morale-boosting exercise and Mrs Clinton was reassured by members that if impeachment was voted through, the president should not resign.

On Friday, Vice President Al Gore told Americans there was no chance of Mr Clinton stepping down voluntarily.

Resignation ruled out

"I think the results of a meteor strike are more likely than the resignation of the president," he said.

But with a Republican majority in Congress, the vote seems certain to go against Mr Clinton.

Republican Asa Hutchison said impeachment was a fitting punishment for the president's alleged crimes.

"I have no problem in setting a standard for future presidents that repeated and intentional acts of perjury in official court proceedings will jeopardise their office," he said.

But Democrat Steven Rothman said voting through the motion "will forever damage the constitutional power in America".

There were small signs of dissent on either side.

Peter King was the first Republican to declare he would vote against impeachment.

Democrats Bill Lipinski and Louise Slaughter suggested that if Mr Clinton were impeached he should follow the example of former president Richard Nixon and resign.

Earlier Democrats had tried to further postpone the debate while American troops were active in the Gulf.

But this was voted down by Republicans keen to press on with proceedings.