Telstra has claimed it has not changed its position on marriage equality after pressure from the Catholic church, despite saying it will not drive further public debate on the issue.

Telstra and many other major corporations have come under pressure from the Catholic church for signing an Australian Marriage Equality petition in favour of same-sex marriage.

In May the Catholic archdiocese of Sydney business manager, Michael Digges, wrote to the corporations to express the church’s “grave concern” and accuse them of “overstepping their purpose”.

In the letter, Digges writes the church is a “significant user of goods and services from many corporations, both local and international” and reminds the firm that many of its “employees, customers, partners, suppliers” would belong to the Catholic faith.

On Wednesday the Australian reported Telstra had retreated from campaigning on marriage equality after pressure from the church and was concerned it would risk its commercial relationship and contracts with Catholic schools.

A Telstra spokesman told Guardian Australia: “The government has committed to putting same-sex marriage before the Australian people in a plebiscite and, ultimately, it will be parliament who determines any changes to the institution of marriage.

“In view of this, Telstra has no further plans to figure prominently in the wider public debate.”

On Wednesday Telstra reiterated the comments on Twitter by saying it had “no plans to driver further public debate”.

The Aus people and Parliament will determine any changes to institution of marriage. We have no plans to drive further public debate. — Telstra News (@Telstra_news) April 12, 2016

“Our position on marriage equality hasn’t changed,” it claimed. “We place great importance on diversity and stand against discrimination in all forms.”

This drew howls of protests from marriage equality supporters on Twitter, who questioned how Telstra could help achieve change without driving public debate.

@Telstra_news Public debate is what drives change!!!! Removing your public support to safe guard your profits says you are cowards. — Dan (@Captain__DMan) April 13, 2016

Some Telstra customers threatened a boycott over the reports.

.@Telstra_news Your organisation appears to be experiencing a reality outage. This "call" will be recorded for boycott purposes. — Peter Fyfe (@FyfePeter) April 13, 2016

The national director of Australian Marriage Equality, Rodney Croome, told Guardian Australia no business, including Telstra, had asked to be taken off its website as a supporter and more supporters come in every day.

“I think that shows the strength of support for marriage equality in the business community,” he said.

Telstra’s logo is still featured on the marriage equality campaign website.

“Many Australian businesses and business leaders support marriage equality because it sends a powerful message to staff and customers about their commitment to a more open and respectful work environment,” Croome said.

The Telstra spokesman said the telco had “demonstrated it places great importance on diversity and standing against discrimination, in all its forms. Our workforce reflects this diversity, including people of same sex in a broad range of relationships.”