Australian Broadcasting Corp chairman Justin Milne has resigned, leaving a leadership vacuum at the national broadcaster after the board’s sacking of managing director Michelle Guthrie on Monday.

Milne’s resignation follows revelations in recent days that he had ordered Guthrie to “get rid of” senior ABC journalist Emma Alberici and “shoot” political editor Andrew Probyn, both allegedly because then Prime Minister Malcolm Turnbull and his federal government “hated” them. 

Prime Minister Scott Morrison today welcomed Milne’s resignation. "ABC board and chairman have made the right call. Time for the ABC to resume normal transmission, both independently and without bias. That is what Australia's taxpayers pay for and deserve." Morrison said. 

Milne’s resignation came as Communications Minister Mitch Fifield announced an inquiry into whether there was any political interference with and whether Milne’s actions breached the independence of the ABC and a hastily convened board meeting at which Milne was not present. 

ABC staff around the country met yesterday to call for an investigation into Milne's actions. 

"Mr. Milne seems to have misunderstood that the role of the ABC is as a public broadcaster, not a mouthpiece for the government of the day," said journalists' union chief executive Paul Murphy.

In resigning, Milne, a longtime friend of Turnbull said that, "It's clearly not a good thing for everyone to be trying to do their job with this kind of firestorm going on, so I wanted to provide a release valve” and denied that the government had told him to fire staff. 

His departure marks four days of turmoil at the national broadcaster, which began with the sudden announcement that Guthrie had departed as managing director halfway through her contract. 

Milne cited the need for ’fresh leadership” for Guthrie’s sacking. "We needed a different leadership style and that is the decision of the board."

Guthrie said she was “devastated” by her departure and was seeking legal advice. She has since hired two high-profile lawyers to look at her case for unfair dismissal.

“While my contract permits the board to terminate my appointment without cause and with immediate effect, I believe there is no justification for the board to trigger that termination clause. I am considering my legal options,” she said.

“I am devastated by the board’s decision to terminate my employment despite no claim of wrongdoing on my part. I wanted to continue the transformation of the ABC.”

On Wednesday Fairfax Media media published a leaked email in which Milne told Guthrie about Alberici,” They (the government) hate her. We are tarred with her brush. I think it's simple. Get rid of her. We need to save the ABC - not Emma (Alberici)."

Turnbull has denied asking for any journalists to be fired, saying he complained about specific errors in ABC stories and that accuracy had “deteriorated over recent years”.