Allegations ABC chairman Justin Milne asked former managing director Michelle Guthrie to fire journalists after speaking with the government have been described as the actions of a "tin-pot dictatorship" by the federal opposition.
"These are not the actions of the Australian democracy," senior Labor frontbencher Penny Wong told ABC radio on Thursday.
Her comments come as former prime minister Malcolm Turnbull denied demanding Ms Guthrie sack chief economics correspondent Emma Alberici over her reporting.
Staff at the ABC have called on chairman Justin Milne to stand aside. Source: AAP
Mr Milne is under mounting pressure to resign over allegations he ordered Ms Guthrie to fire Ms Alberici and ABC political editor Andrew Probyn because the coalition had taken issue with them.
An email has shown Mr Milne asked Ms Guthrie - who was herself sacked on Monday - to fire Ms Alberici in May.
"They [the government] hate her," he wrote in an email to Ms Guthrie obtained by Fairfax Media.
The chairman is also said to have ordered Ms Guthrie sack Mr Probyn by telling her "you just have to shoot him", because Mr Turnbull hated the journalist.
But he rejects asking for specific reporters to be axed.
"That is not right. The bottom line is I have never called for anybody to be fired," Mr Turnbull told reporters in New York.
ABC board chairman Justin Milne. Source: AAP
"My concern has been on the accuracy and impartiality of news reporting."
Ms Wong said despite Mr Turnbull's claims, it appeared Mr Milne spoke with the former prime minister and a Liberal minister before seeking to have a journalist sacked.
Mr Milne must explain himself publicly, she said.
"These are the actions of a tin-pot dictatorship."
Communications Minister Mitch Fifield has announced his department secretary will run an inquiry into the matter and report as soon as possible.
But Labor and the Greens are pushing for a Senate inquiry into Mr Milne's conduct, hoping to trigger it before federal parliament resumes in mid-October.
Greens Senator Sarah Hanson-Young has called for the full ABC board to be overhauled to give the broadcaster a "fresh start".
"It's not just the chair. The rest of the board need to consider their positions," she told the ABC on Thursday.
The search for the ABC's next managing director has begun after Michelle Guthrie was sacked. Source: AAP
ABC executives will appear before a Senate estimates committee on October 22 and 23.
The broadcaster's staff on Wednesday unanimously voted for Mr Milne to step down while the departmental investigation takes place, but the board has confidence in him to continue in his job.
ABC News Director Gaven Morris says he has told staff to hold their heads high and do their jobs well amidst the latest stories.
"Your bosses are the Australian people," he wrote on Twitter on Thursday.
