One of Australia’s best-known Catholics, Father Bob Macguire, has urged his fellow clergy to “shut our mouths” after the Archbishop of Brisbane cited society’s refusal to allow parents to marry their children to argue why same-sex couples do not “qualify” for marriage.

Archbishop Mark Coleridge made the controversial comparison –described as “offensive” by ‘Yes’ campaigners – in an interview with the ABC on Tuesday.

Archbishop Coleridge argued that human beings had “always discriminated” about who could marry whom.

“Parents can’t marry their children, children can’t marry their parents … sibling marrying sibling has always been ruled out,” he said.

Asked if the comparison was inappropriate, Archbishop Coleridge responded: “It’s not exactly the same but I wouldn’t presume immediately that they might want.”

“Sibling marrying sibling has always been ruled out. People under age have been disqualified from marrying. But so, too, people of the same sex.

“But that is not to say that they are not equal. It’s simply saying that they are not the same and that they don’t qualify for what we call marriage.”

Father Bob Mcguire: ‘We should shut our mouths’

In his first public comments on the postal survey campaign, Father Maguire told The New Daily the Archbishop’s interview showed why “clergy are the worst politicians”.

Father Maguire, a former Melbourne parish priest and community worker who rose to prominence as a media personality, said he believed Archbishop Coleridge had been trying to “present the church’s case in marketable terms”.

“They (the church) should really consider whether they’re getting value from their media people,” he said.

“I like Mark Coleridge … But when it comes to these issues I think we should shut our mouths.

Archbishop Mark Coleridge has been slammed over his same-sex marriage comments. Photo: AAP

“He (Archbishop Coleridge) will have a big number of people that would want to hear a strong line.

“But it would be better if the church and other religions were involved in pastoral care with their communities rather than in politics.”

Father Maguire said the postal survey provided the church with an opportunity to show “more compassion than we did during the other issue”.

He had no problem with same-sex marriage becoming secular law and said the debate was one for the “secular world”.

Though he added that when clergy, including leaders like Archbishop Coleridge, were “in church and have a congregation” they were “obliged to give leadership”.

Archbishop Coleridge’s remarks on Tuesday reflect views he expressed in a pastoral letter distributed within the Brisbane Archdiocese earlier in the month.

A spokeswoman for the Coalition for Marriage campaign defended the Archbishop on Tuesday night.

“It is clear that the Archbishop was trying to explain that there have always been certain couples who are ineligible to be married under Australian law, but that this was not a comment on their equality as persons,” a spokeswoman said.

“To suggest he was finding an equivalence between incestuous and same-sex couples is an unfair representation of his comments, and not worthy of such an important debate.”

Acting Special Minister of State Mathias Cormann told ABC Radio that nobody was suggesting “parents should be able to marry their children”.

“The question in front of Australians is not any of the examples that were mentioned there,” said Senator Cormann, who opposes a change in the law but is not campaigning because he is responsible for overseeing the survey.

On Tuesday, veteran gay rights activist Rodney Croome told The New Daily that the ‘Yes’ campaign needed to change tack to combat “misinformation” from same-sex marriage opponents.

But ‘Yes’ campaigners will be buoyed by a new poll that showed support for same-sex marriage up three percentage points from last week to 58 per cent, compared with 33 per cent who oppose it.

Though the ‘Yes’ side has been consistently ahead, Tuesday’s Essential survey marks a turnaround after a string of polls found the ‘No’ camp gaining ground.