Qantas boss Alan Joyce has told reporters he intends to press charges against the Perth man who shoved a pie in his face on Tuesday morning while he was speaking at a conference.

Tony Overheu, who carried out the stunt, told the Breakfast program on Radio 6PR on Wednesday he did it to stand up to "corporate bullying" which promoted marriage equality.

The 67-year-old has since emailed an apology to Mr Joyce after his wife was "at his throat" over his actions.

The Willetton man was caught on film emerging from behind a curtain at a business breakfast event hosted by The West Australian at the Hyatt Regency on Tuesday morning.