ABC's brutal ultimatum to George Stephanopoulos after his damning verdict on Joe Biden - as network plunged into 'fully-fledged crisis'

George Stephanopoulos was threatened with being taken off air if he didn't clarify his position on Joe Biden's ability to serve another four years.

The ABC host gave his blunt assessment of the president's performance in a brief interview when he was ambushed on Tuesday.

The former Bill Clinton aide was asked on the street in Manhattan if Biden should step down and responded: 'I don't think he can serve four more years'.

Biden's interview with the former White House press secretary on Friday followed a disastrous debate performance on June 27.

Stephanopoulos, 63, appeared to quickly regret his off-the-cuff remark and offered a statement of regret.

'Earlier today I responded to a question from a passerby. I shouldn't have,' he said. 

ABC News issued their own statement, saying, 'George expressed his own point of view and not the position of ABC News.'

What the two statements didn't reveal was the crisis Stephanopoulos' nine words kicked off at the highest level of the major network.

News division president Debra O'Connell called a panicked meeting with advisers and executives on Tuesday night, including public relations consultants.

'This was a fully-fledged crisis and it exploded with far-reaching reverberations,' an insider claimed to Radar Online.

She then hauled Stephanopoulos into a private meeting where she gave him an ultimatum: apologize or be yanked off air.

Stephanopoulos both hosts Good Morning America and is a moderator on current affairs panel show This Week.

ABC bosses were concerned the veteran broadcaster had expressed a private opinion that would fatally undermine his appearance of objectivity.

'[O'Connell told him] in no uncertain terms that he is a newsman who is expected to be objective,' the insider said.

'She was furious that someone of George's experience and status would compromise the news division's impartiality, and subject it to unnecessary and embarrassing headlines.

'George backed Debra into a corner. If he did not apologize, how could he continue with his duties at ABC News without the network facing an avalanche of criticism.'

The insider, however, believed that even though Stephanopoulos backed away from his comment and 'minimized it as a quip', ABC bosses knew the damage was done.

'You can expect the Trump campaign and GOP to seize on this. You can also expect the White House to avoid ABC News moving forward. Biden will never sit down with Stephanopoulos ever again,' they said.

Biden's cognitive function has been under intense scrutiny since his car crash presidential debate against Donald Trump last month.

Friday, he attempted some damage control with a sit down interview with ABC  - a performance that was once again panned by members of his own party.

Biden made it through the 22-minute ABC News interview on Friday without any major blunders.

But it appeared unlikely to fully tamp down concerns about his age, or his ability to defeat Trump on November 5.

The floundering has led to calls for Biden to withdraw from the race, but he has so far remained steadfast in his commitment to standing. 

In looking ahead, a senior Democratic aide told ABC News that the president should 'buckle up for a wild week.'

Many hoped Friday's interview with Stephanopoulos would be a chance for Biden, 81, to prove the debate was a one-off.

But the toe-curling performance, which included responding to questions in a raspy voice, losing track mid-sentence and going off on tangents, had many Democrats unconvinced.

The president has remained adamant he's staying in the race since the interview. 

Some prominent Democrats are desperately looking for possible alternatives should Biden exit the race.