The ABC is "hostile territory" for conservative politicians, says Peter Costello in his latest op-ed. "With the ABC," Costello wrote this week for Fairfax, "the line of questioning is always predictable. It always comes from the Labor/Green perspective."

The former Treasurer says he decided to unveil his insights into institutional bias at the ABC because, "I am not now at the mercy of the media so I can afford to say what everyone on the conservative side of politics knows."