Asked about this, French said: “I wouldn’t think that that gloomy prognosis is a probable one.”

French acknowledged, however, that some litigants might challenge decisions by the Voice in the courts.

“I wouldn’t say that there won’t be litigation in somebody’s mind. And sometimes there’s litigation which is quixotic and hopeless, sometimes there’s litigation which has a reasonable point,” he said.

“As a former judge, I would never promise absolute certainty. If you have a lawyer who says to you, ‘we are certain to win,’ you must change your lawyer because there are often reasonable arguments on both sides.

“But for me, it’s a matter of assessing the risk against the return. I see the risk as low, very low, compared with the potential benefit of the outcome.”

Pointing to Australian history and the crafting of the constitution in the 1890s, French compared some of the arguments against federation – including that people did not understand the proposal – with the claims made against the Voice.

French rejected the attack line from the No side that “if you don’t know, vote No”.

“The Australian spirit evoked by the ‘don’t know’ slogan is a poor shadow of the spirit which drew up our constitution,” he said.

“It invites us to a resentful, uninquiring passivity. Australians, whether they vote Yes or No, are better than that.”

Asked about his use of the word “weaponisation” to describe some of the argument against the Voice, he said many of the debates about the proposed body were about personal attacks rather than the substance of the change.

“We have a political system which has a natural adversarialism built into it, but I feel we are moving into a deeper polarisation, not least social and social media space, which really does change the nature of our discourse,” he said.

“On one end of the spectrum, you might have people who feel that their first order interests are not being addressed, and that the great and the good are engaged in debate about second order interests.

“And the last thing that will succeed in engaging those people is what I call the unctious judgmentalism of the progressive.

“And the problem is that once that sets in it tends to become a bit entrenched, and I think we’re seeing that in spades in the US, and I think it does erode our democratic fabric in a way – that we lose our capacity to disagree reasonably.”