Deputy Prime Minister Barnaby Joyce, who is also leader of junior Coalition partner The Nationals, is the latest cabinet minister to declare he will back a majority yes vote in parliament.

Mr Joyce pledged to put aside his personal support for the status quo definition of marriage if a planned plebiscite decides the other way.

“I will follow the instructions of the Australian people,” he told ABC radio yesterday.

Mr Joyce joins cabinet colleagues Scott Morrison and Mathias Cormann, also supporters of traditional marriage, who have declared they will respect the majority view.

“Whatever the result at that plebiscite, I am very confident it will be respected by the Australian parliament,” Senator Cormann told reporters in Canberra.

The position of three of the Coalition’s most senior figures is at odds with the view of Tony Abbott’s former chief of staff Peta Credlin.

She has warned of a “schism” in the Coalition over its plebiscite plan, predicting any enabling legislation could fail to pass parliament.

Ms Credlin said it was very likely the legislation would be opposed by the Greens and Labor.

She told Sky News Mr Turnbull would make a “cursory attempt” at passing the enabling legislation “and if that fails, he has made it very clear he wants a result by the end of the year”.

“I think it will be a very big schism inside the Liberal Party, going back to territory of 2009. Malcolm knows that very well, because that’s where he lost his leadership,” she said.