In the vote in the UN disarmament and international security committee on Thursday, 123 nations were in favour of the resolution, 38 opposed and 16 abstained.
Nuclear powers the United States, Russia, Israel, France and the United Kingdom were among those that opposed the measure.
Australia, as forecast last week, and as a long-time dependant on the US’s extended nuclear deterrence, also voted no.
The resolution now goes to a full general assembly vote some time in December.
The resolution aims to hold a conference in March 2017 to negotiate a “legally binding instrument to prohibit nuclear weapons, leading towards their total elimination”.
Support for a ban treaty has been growing steadily over months of negotiations, but it has no support from the nine known nuclear states – the US, China, France, Britain, Russia, India, Pakistan, Israel and North Korea – which includes the veto-wielding permanent five members of the security council.
But Australia has been the most outspoken of the non-nuclear states.
During months of negotiations, Australia has lobbied other countries, pressing the case for what it describes as a “building blocks” approach of engaging with nuclear powers to reduce the global stockpile of 15,000 weapons.
Australia has consistently maintained that as long as nuclear weapons exist, it must rely on the protection of the deterrent effect of the US’s nuclear arsenal, the second largest in the world.
When he appeared before Senate estimates last week, the Department of Foreign Affairs and Trade’s assistant secretary, Richard Sadleir, forecast Australia’s rejection of the vote: “Consistent with the position to that we took to the open-ended working group (into nuclear disarmament) report, we will be voting no with respect to that resolution.”
Sadleir said Australia’s position on nuclear disarmament was “consistent and clear”.
“We do not support a ban treaty,” he said. “A ban treaty that does not include the nuclear weapons states, those states which possess nuclear weapons, and is disconnected from the rest of the security environment, would be counterproductive and not lead to reductions in nuclear arsenals.”
Professor Tilman Ruff, founding chair of the International Campaign to Abolish Nuclear Weapons and co-president of the International Physicians for the Prevention of Nuclear War, said the vote was a “historic step” for the world that “heralds an end to two decades of paralysis in multilateral nuclear disarmament”.
“The numbers are especially encouraging given the ferocious pressure on countries to vote no by the nuclear-armed states, who see that this will fundamentally challenge their continued possession of nuclear weapons,” he said.
“The treaty will fill the legal gap by which the most destructive of all weapons – nuclear weapons – are the only weapon of mass destruction to not yet be outlawed by international treaty.”
Ruff said Australia should reverse its opposition “and get on the right side of humanity”.
“Australia is doing dirty work for Washington, and is willing for US nuclear weapons to be used on its behalf, and potentially with its assistance,” he said.
“It is inconceivable that Australia would not eventually sign up to a treaty prohibiting the last to be banned and worst [weapons of mass destruction]. We’ve signed every other treaty banning an unacceptable weapon, and on some, like chemical weapons, we were a leader.”
Ruff said that given there were no nuclear disarmament negotiations under way or planned, a ban treaty was the only feasible path towards ridding the world of nuclear weapons available now.
The efficacy of a ban treaty is a matter of fierce debate.
Without the participation of the states that actually possess nuclear weapons, critics argue it cannot succeed. But proponents say a nuclear weapons ban will create moral suasion – in the vein of the cluster and landmine conventions – for nuclear weapons states to disarm, and establish an international norm prohibiting nuclear weapons’ development, possession and use.
Non-nuclear states have expressed increasing frustration with the current nuclear regime and the sclerotic movement towards disarmament.
With nuclear weapons states modernising and in some cases increasing their arsenals, instead of discarding them, more states are becoming disenchanted with the nuclear non-proliferation treaty and lending their support for an outright ban.