Peter Dutton targets Joyce over gay marriage

Immigration Minister Peter Dutton has singled out Qantas chief executive Alan Joyce in a fresh assault on the involvement of some of Australia's largest companies in the marriage equality debate.

Mr Dutton warned CEO's to "stick to their knitting", and said the Turnbull government "would not be bullied" into changing its stance on gay marriage.

"It is unacceptable that people have used companies, and shareholders money, to try to throw their weight around in these debates," he said in Cairns following his address to the Liberal National Party's state council.

He used his address on Saturday to accuse chief executives of using shareholders' money to drive a personal agenda.

In particular, he took aim at Qantas chief executive Alan Joyce, a strong advocate for marriage equality.

"Alan Joyce, the individual, is perfectly entitled to campaign for and spend his hard-earned money on any issue he sees fit, but don't do it in the official capacity and with shareholders money," he told the meeting.

"And certainly don't use an iconic brand and the might of a multi-billion dollar business on issues best left to the judgment of issues and elected decision-makers," he said to applause.

Mr Dutton's comments come after the chief executives of 30 of Australia's largest companies, including Telstra, Holden, Wesfarmers and the Commonwealth Bank, urged the government to take action on marriage equality.

The immigration minister, one of the most prominent conservative voices in the Turnbull government, also claimed some companies had been coerced into supporting the marriage equality campaign.

"The reality is that some companies are morally coerced into supporting campaigns in fear of being extorted by an online social media push to boycott their product," he said.