Australian prime minister Tony Abbott has acknowledged the role he played in the Coalition party room’s vote against a free vote on gay marriage.

On Wednesday, Mr Abbott said he made “the best call” to include the National Party in the decision, to the ire of frontbench MPs like Christoper Pyne.

He also appeared to firm his support for a public vote on the issue to legalise same-sex unions.

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“I am the leader, I had to make a call and I think this is the best call,” Mr Abbott told ABC Radio on Wednesday morning.

“There is the prospect of change in the next parliament if that is the will of the Australian people”, referring to his proposal for a national non-binding vote.

“Every time a party leader has to handle a difficult issue some people say well, it should have been done this way, it should have been done that way.” 

However, commentators and Mr Abbott’s Opposition rivals criticised the leadership he has shown over the issue.

“Abbott’s own position has been weakened further in his caucus with MPs furious at his ‘tricky’ use of a third party to carry his will,” Fairfax Media politics editor Mark Kenny wrote.

Deputy Leader of the Opposition Tanya Plibersek said Mr Abbott’s wish to have a national vote on the matter was a waste of taxpayers money.

“We make important decisions in this Parliament everyday,” she said. “The idea that this parliament can’t be trusted to make a decision on marriage equality is laughable.”

“If this was voted on in the Parliament with a free vote on both sides, this change would pass.”

In recent times Mr Abbott has refrained from passing comment on the same-sex marriage push – except to re-enforce where he stands – but on Wednesday morning he conceded attitudes are changing. 

“Please, let’s not underestimate the magnitude of this as a cultural shift,” he said. “Same-sex marriage is something which has only very recently come into our intellectual and cultural parameters.

“Given that it’s really only this generation that has ever thought of this, why not give it to the people?

“Clearly marriage is between a man and a woman.”