An ex-PM, Facebook, three former newspaper editors and an American academic are among those due to speak when Australia’s senate inquiry into media diversity resumes tomorrow.

The third day’s hearings see former prime minister and internet entrepreneur Malcolm Turnbull take centre stage via videoconference (9am) in the hearings chaired by senator Sarah Hanson-Young.

Also appearing virtually is Dr Michael Mann, distinguished professor of atmospheric science at Penn State University, USA, (10.40am).

From Facebook (11.30am until lunch) are APAC policy vice president Simon Milner and Mia Garlick, who is director of policy for Australia, New Zealand & Pacific Islands.

Three regional TV chiefs due to front up at 1.40pm are WIN TV’s Andrew Lancaster, Prime Media’s Ian Audsley and Imparja’s Alistair Feehan.

The temperature may rise later in the afternoon when three perhaps disaffected former editors share an hour of the hearing’s time from 2.40pm. They are Bruce Guthrie, co-founder and now editorial director of The New Daily, Crikey’s Peter Fray, and co-founder of The Conversation Andrew Jaspan. All appear in their private capacities.

Guthrie is author of ‘Man Bites Murdoch’, a 2010 account of his time as editor of the (Melbourne) Herald Sun and the court battle which followed it.

You can watch Monday’s proceedings here.