Mayne also regularly runs for elections to the board of directors of various Australian public companies to draw attention to issues concerning good corporate governance.

[6] In 1999, Mayne resigned from his job at The Australian Financial Review in order to run against then Premier of Victoria Jeff Kennett as an independent protest candidate.

[citation needed] Mayne later ran as an independent in a subsequent Burwood by-election, caused by Kennett's resignation from politics after his 1999 state election loss.

[citation needed] At the 2007 federal election, Mayne ran as an independent for the seat of Higgins against incumbent deputy Liberal leader and treasurer Peter Costello.

Media reports at the time had him in with a chance to win the balance of power but he failed to pull ahead of either Family First or the Green surplus and the final spot went to Liberal Craig Ondarchie.

Between 2011 and 2014, Mayne worked for the Australian Shareholders Association, first as a volunteer director and later as a paid consultant performing the role of spokesman and Policy and Engagement Coordinator.

[10][12] Australian journalism's most prestigious night descended into a shambles when Glenn Milne pushed Mayne off the stage at the 2006 Walkley Awards.

[13] As Mayne prepared to present an award to Morgan Mellish of The Australian Financial Review,[14] a "red-faced"[13] and "seemingly intoxicated"[15] Milne lurched onto the stage and began a diatribe of verbal abuse.

"[15] Recalling the incident, where he suffered a sore ankle from the altercation,[17] Mayne stated:[15] "I could see from his sort of wild eyes, and his red face, that he was clearly very drunk, and I thought, you know, heck, this is going to be out of control,...... And next thing I know, I'd been shoved off the stage and I was hurtling through the air, in a four-foot drop onto the floor.