More than 230 former ABC News correspondents, executives and producers have signed a letter urging the US network's current top executive to take a firm stand against any Trump administration effort to curtail press access.
The letter, which circulated on a Facebook forum for ex-ABC News employees, was written after White House press secretary Sean Spicer held an informal briefing last Friday excluding several news organisations that have done stories angering President Donald Trump and his team.
Signees asked ABC News president James Goldston to "take a public stand. Refuse to take part in any future White House briefings based on an invitation list of who's in/who's out".
"We've expressed our concerns to the White House that it operates in a way that's open, transparent and fair," Mr Goldston said.
"And we will continue to stand with our colleagues who cover the White House and to protest when any government official fails to live up to those standards."
Signees include Reagan-era White House correspondent Sam Donaldson and former ABC reporters Ken Kashiwahara, Jeanne Meserve and Lynn Sherr.
Among the executives are four former executive producers of World News Tonight and top leaders at Nightline, 20/20 and Good Morning America.
Prominent news executives Rick Kaplan, Bill Lord, Paul Friedman, Av Westin and Tom Yellin also signed, along with documentarian and the late anchor Peter Jennings's widow, Kayce Freed Jennings.
The letter called last Friday's incident "an alarming new development enacted by an administration that has declared war on respected news outlets".
Mr Trump has included ABC News in his labelling of media organisations that are the "enemy of the American people" and "fake news".
ABC was included in Mr Spicer's briefing last Friday, where access was denied to CNN, The New York Times, Los Angeles Times, Politico and BuzzFeed.
Reporters from other organisations, including The Associated Press, USA Today and Time magazine, refused to attend the briefing in protest.
The ABC News reporter in the briefing, Cecilia Vega, asked Mr Spicer why the other news organisations were excluded and shared audio of the briefing with people who were not included.
The White House has said that with space limited in Mr Spicer's office, they included "pool" reporters who share information in instances where there is not enough room for the entire press corps.
In calling for Mr Goldston to speak out, the letter from former ABC Newsers noted a strong public protest by Dean Baquet, executive editor of The New York Times, and statements by The Wall Street Journal and Bloomberg that they would not participate in future briefing where reporters are barred.