Clive Myrie in Washington: "Uncharted territory"

Mr Clinton's lawyers have begun work on his defence for the impending trial in the Senate.

At the same time, his political supporters are continuing to press for censure - a compromise solution - rather than a trial.

The US House of Representatives voted on Saturday to impeach Mr Clinton on two charges after a bitter debate which split along party lines.

The BBC's Tom Carver: The president's approval rating has risen

Shortly afterwards, Mr Clinton - the first US president this century to be impeached - told the nation he would not resign.

Opinion polls taken in the wake of the vote showed Mr Clinton's approval rating has actually risen. An NBC News poll showed 72% approved of Mr Clinton's handling of the presidency, a rise of four points from Tuesday.

On Sunday, Mr Clinton and his daughter, Chelsea, attended a Washington Methodist church, where he waved at supporters - and avoided one man calling for his resignation.

White House strategies

President Clinton's legal team will work through Christmas preparing his defence.

In a television interview, White House Special Counsel Greg Craig said no decision had been taken yet on what witnesses Mr Clinton will call.

He added that it would up to the prosecution to prove the case against Mr Clinton, and predicted that would be a difficult task.

While his legal team prepares for a trial, White House officials are trying to head off the possibility of a legal hearing.

White House Chief of Staff John Podesta said he was confident the Senate could find a solution that would avoid a trial.

Democratic Senator Christopher Dodd said he would back censure because a trial would "tie up three branches of government for the next four months".

Republican Arlen Spector: "Censure not worth a tinker's damn"

Another Democratic Senator, Patrick Leahy, said: "The determination had been made in the House that they were going to have impeachment, come hell or high water. I think we can restore political sanity in the Senate."

But many Republican senators are publicly ruling out censure.

Don Nickles, the number two Republican in the Senate, said a deal that would avoid a trial was unlikely.

And the Texan Republican, Kay Bailey Hutchison, insisted it would be "honourable" for Clinton to step down and hand over the presidency to Vice President Al Gore.

Perjury and obstruction

Mr Clinton is facing charges of perjury and obstruction of justice in connection with his affair with Monica Lewinsky.

A Senate trial would be presided over by Supreme Court Chief Justice William Rehnquist. The 100-member Senate would serve as the jury, with a two-thirds majority needed to convict the president and remove him from office.

To secure such a majority, Senate Republicans would have to attract at least 12 Democrats.

However, the BBC diplomatic correspondent says the most likely outcome is a vote largely along party lines and an even more damaged president, who somehow hangs on.