Donald Trump has said he will "never withdraw" from the race for the White House despite growing calls from within his own party to step aside.

The Republican presidential hopeful was forced to tell the Wall Street Journal there was "zero chance I'll quit" amid a fierce backlash over his degrading remarks about groping women.

Dozens of senior party figures, including Congressmen and Senators, have said they were no longer able to endorse him and pulled their support following the release of a 2005 recording in which Mr Trump makes obscene sex boasts.

Republican Congressman Jason Chaffetz

House speaker Paul Ryan has said he was "sickened" by Mr Trump's comments and withdrew an invitation to the candidate to attend a campaign event.

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Speaking at the rally, Mr Ryan referred to the controversy, but notably did not mention Mr Trump by name.

He told supporters: "Let me just start off by saying that there is a bit of an elephant in the room.

"It is a troubling situation and I am serious - it is.

"I meant what I said and it's still how I feel, but that is not what we are here to talk about today."

As proud as I am to label myself a Republican, there is one label that I hold above all else - American. My full statement: pic.twitter.com/biRvY8S3aZ — Arnold (@Schwarzenegger) October 8, 2016

Other leading figures, including former California governor Arnold Schwarzeneggar and Senator John McCain, said they could no longer back their Republican colleague.

Meanwhile, Mr Ryan's fundraising chief Spencer Zwick said he had been fielding calls from donors who "want help putting money together to fund a new person to be the GOP nominee".

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Mr Trump's wife Melania, who he was only newly married to at the time of the recording, has described her husband's comments as "unacceptable and offensive", but said she had accepted his apology.

The tycoon's running mate, Mike Pence, who many of the Republicans said should now be on the nomination, also put out a statement saying he could not condone or defend the nominee's comments about women.

Trump: I was wrong and I apologise

Mr Trump was caught on a microphone as he arrived on the set of daytime soap opera Days Of Our Lives for a cameo.

He was telling Billy Bush of the celebrity show Access Hollywood about a woman he tried to seduce.

He is heard to say: "I did try and f*** her. She was married.

"I moved on her like a b****, but I couldn't get there."

He also brags about women letting him kiss and grope them because he is famous.

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Mr Trump said: "I just start kissing them. And when you're a star they let you do it.

"Grab them by the p****. You can do anything."

Following the release of the 2005 video, the Republican presidential hopeful initially said he was sorry "if anyone was offended" by the "locker room banter".

But as the crisis escalated, he later added: "Anyone who knows me knows these words don't reflect who I am. I said it, I was wrong and I apologise."

Mr Schwarzeneggar said: "For the first time since I became a citizen in 1983, I will not vote for the Republican candidate for President."

Senator McCain said: "Donald Trump's behavior 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."

Responding to the release of the video, Senator Mike Crapo said: "I have reached a decision that I can no longer endorse Donald Trump. His pattern of behavior leaves me no choice. I urge Donald Trump to stand aside."

The running mate of former Republican hopeful Ted Cruz, Carly Fiorina, said: "Donald Trump does not understand me or my party. I ask Donald Trump to step aside and for RNC to replace him with Gov Mike Pence."

The second debate with Democratic presidential candidate Hillary Clinton is due to take place on Sunday.