WASHINGTON • Republican leaders have been deserting their presidential nominee Donald Trump by the dozen since the release of a video showing him speaking of women in vulgar sexual terms late last week.

Not only did the latest controversy deliver a punishing blow to Mr Trump's campaign, but it has also plunged the party into crisis a month before the Nov 8 election.

Fearing that his candidacy was on the verge of undermining the entire Republican ticket, a group of senators, including Mr John McCain, and House members withdrew their support, with some demanding that he step aside.

Mr Trump, however, vowed to stay in the race, saying he has "tremendous support". Yesterday, he shot back at those who have withdrawn support for him, saying on Twitter: "So many self-righteous hypocrites. Watch their poll numbers - and elections - go down!"

Earlier, Mr McCain, the party's 2008 presidential nominee, said: "Donald Trump's behaviour this week, concluding with the disclosure of his demeaning comments about women and his boasts about sexual assaults, make it impossible to continue to offer even conditional support for his candidacy."

And in an unheard-of rebuke by a running mate, Republican vice- presidential candidate Mike Pence declined to appear on Mr Trump's behalf at a party gathering in Wisconsin. "I do not condone his remarks and cannot defend them," said the Indiana governor.

Mr Trump's wife Melania urged voters to support him despite saying his remarks were "unacceptable and offensive to me".

"I hope people will accept his apology, as I have, and focus on the important issues facing our nation and the world," she said in a statement.

By Saturday evening, no fewer than 36 Republican members of Congress and governors, who had not previously ruled out supporting Mr Trump, disavowed his candidacy - an unprecedented desertion by the party of its standard-bearer.

Trump aides described him as shaken, watching news coverage of the video with a mixture of disbelief and horror. He apologised in a videotaped statement, saying: "I've said and done things I regret, and the words released today on this more-than-a-decade-old video are one of them." In a brief telephone interview on Saturday, he also said he would "never drop out of this race in a million years".

But the situation has grown so dire that many in the party are all but pleading with him to withdraw and let Mr Pence serve as the presidential nominee, though this is easier said than done.

Senator Kelly Ayotte, facing a competitive re-election in battleground state New Hampshire, announced that she would no longer back Mr Trump and would write in Mr Pence for president instead.

Then more damaging news emerged, with a CNN report on the many lewd and tasteless comments Mr Trump had made over the years on The Howard Stern Show.

But top Trump adviser and former New York mayor Rudy Giuliani was defiant in his appearances on Sunday talk shows, saying Mr Trump would not rule out going on the offensive against Democratic presidential nominee Hillary Clinton in Sunday night's presidential debate (9am Singapore time today) by bringing up her husband Bill Clinton's past infidelities.

A Reuters-Ipsos poll had Mrs Clinton leading by five points on Friday, before the video surfaced, adding an air of unpredictability to the debate. The town hall-style debate will have undecided voters posing half of the questions and two moderators posing the others.

NYTIMES, REUTERS