Fairfax Media reported that the Archdiocese contacted Qantas chief executive Alan Joyce and SBS chief executive Michael Ebeid, urging them to reconsider their public endorsement of same-sex marriage.

Both companies were among hundreds of Australian corporations to pledge their support for the Australian Marriage Equality campaign last year, and both chief executives addressed a high-profile breakfast hosted by the AME in May.

Shortly after the AME campaign was launched, the Archdiocese addressed letters to many of the organisations involved, including Qantas, SBS, Telstra, the Football Federation of Australia and law firm Maurice Blackburn.

"I wonder whether you have questioned whether it is the role of a corporation such as yours to be participating in such an important matter that impacts all of Australian society now and into the future," wrote Sydney Archdiocese business manager Michael Digges.