Mandie Sami reported this story on Wednesday, June 24, 2015 12:35:00

KIM LANDERS: The Catholic Church in Sydney is sending letters to companies that publicly support marriage equality, expressing its grave concern about their stance.



It has targeted some of the 150 businesses that put their names and logos to recent newspaper ads supporting marriage equality.



The ABC has seen one letter where the Catholic Church reminds a company of the church's purchasing power.



Mandie Sami explains.



MANDIE SAMI: The ABC hasn't been able to verify how many of the businesses were sent the letter but it has seen what was sent to at least one of them.



The letter was sent by Michael Diggs, who's the business manager for the Catholic archdiocese of Sydney.



He addressed it to Steve Walsh, who's the chairman of partners at Maurice Blackburn law firm.



Here's an excerpt.



MICHAEL DIGGS LETTER (voiceover): You may be aware that the Catholic archdiocese of Sydney is significant user of goods and services from many corporations, both local and international.



With a Catholic population of 600,000 people within the archdiocese, accounting for 26.7 per cent of the total population, it's the largest Catholic diocese in New South Wales.



I only mention this to indicate the diverse and expansive demographic we serve.



Undoubtedly, many of the Catholic population of Sydney would be your employees, customers, partners, suppliers.



It's therefore with grave concern that I write to you about the marriage quality of Australians campaign.



You are publically supporting a strategic, political and well-funded campaign designed to pressure the Federal Government into changing the Marriage Act.



For a corporation to speak on such issues is indeed overstepping their purpose and it is to be strongly resisted.



MANDIE SAMI: The ABC requested an interview with Michael Diggs to find out how many businesses were sent this letter.



But he was "unavailable".



Maurice Blackburn principal, Liberty Sanger, says she's not sure what the intention of the letter was, but either way the law firm won't be intimidated.



LIBERTY SANGER: I thought it was a very heavy-handed response and un-called for because we're very respectful of everybody's points of view in this debate.



In Ireland, we saw that people turned out in droves against the express wishes of the Catholic Church and voted 'yes' for marriage equality.



So I think that he needs to be very careful and considered about the tone he adopts.



If it was his intention to make us think that he was going to be able to keep Catholics away from Maurice Blackburn because of our support for marriage equality, then I think he will be sadly mistaken, and I don't think it's helpful to be making those sorts of comments.



Whether or not it was intended as a threat, I'll leave for him to comment upon, but I don't think that's very helpful; it's certainly not respectful.



We're not asking people to stay away from the Catholic Church - quite the opposite.



We're simply saying that for 100 odd years, we've been fighting for people to have equal treatment before the law.



This is yet another example of where such treatment needs to be corrected, and we'd like the Parliament of Australia to act.



MANDIE SAMI: Does he owe the companies that this letter has been sent to an apology?



LIBERTY SANGER: Look, that's a good question.



I'm not in the business of punishing people for having a view and asserting that view.



Everyone's entitled to do that.



So I don't... I'm not asking for him to apologise to us.



I think the important thing is that we continue to show our support so that others who have the same view as us have the courage to speak up and encourage parliamentarians to make the right decision in the Parliament.



MANDIE SAMI: Earlier this month, the Australian Catholic Bishops Conference sent a 15-page pamphlet called ‘Don't Mess with Marriage’ home with schoolchildren at Catholic schools across the country.



Ms Sanger says the Catholic Church has a right to express its view, but not to attempt to intimidate others.



LIBERTY SANGER: I really have to question what they hoped to achieve by sending the letter.



The original advertisement was very tame.



It simply listed, with company logos, a whole lot of businesses that supported marriage equality, and made the point that very soon that they would need a bigger ad.



It wasn't provocative, it was a very respectful ad, it wasn't trying to upset the Catholic Church.



It seems the response is over the top to me.



Now it may well be that their intention was to try and frighten us into not participating in the debate.



If that was the objective, well it's obviously had the opposite effect.



We don't think that there's any need for a heavy-handed response.



We're very happy to talk to anyone about our views on marriage equality



If they want to have a chat, they can pick up the phone and we're happy to have that chat.



KIM LANDERS: Liberty Sanger from Maurice Blackburn ending Mandie Sami's report.