Federal Agriculture Minister Barnaby Joyce has warned Asian countries could see Australia as "decadent" if moves to legalise same-sex marriage are successful.

Mr Joyce was asked about comments last week by another frontbencher opposed to gay marriage, Eric Abetz, who is the Leader of the Government in the Senate.

Senator Abetz suggested that if Asian countries did not accept same-sex marriage then Australia should not either, pointing to the often-repeated phrase that for Australia this was the Asian century.

"Eric is right in saying where we live economically is south east Asia, that's where our cattle go," Mr Joyce told the ABC's Insiders program.

"When we go there, there are judgments whether you like it or not that are made about us.

"They see us as decadent."

Insiders host Barry Cassidy asked: "So would they see us embracing gay marriage as decadence?"

"I think that in some instances they would, yeah," Mr Joyce replied.

He added he did not believe marriage should be redefined by the legislation.

"I don't think if you go and pass a piece of legislation and say a diamond is a square makes diamonds squares — they're two different things," he said.

"It's not making a value judgement about either."

Mr Joyce went on to say he viewed marriage as "a process that's inherently there for the support of ... or the prospect of ... or the opportunity of children".

"I think that every child has a right, absolute right to know her or his mother and father and also ... should be given the greatest opportunity to know their biological mother and father," Mr Joyce said.

The issue of gay marriage has been back on the agenda, with confirmation last week that Liberal MP Warren Entsch planned to introduce a private member's bill to legalise same-sex marriage, with cross-party sponsorship, when Parliament resumes next month.

Before the last election Prime Minister Tony Abbott promised to allow the Coalition party room to decide if government MPs and senators should be allowed a conscience vote on the issue, which if it was allowed would give the bill a chance of passing.

However last week Mr Abbott played down the chances of the private member's bill being debated and put to a vote.

"It's quite unusual for private member's bills to come on for debate and vote in the Parliament," he said on Thursday.