Australia is working on a new nuclear deal with the United Kingdom once it leaves the European Union.

One fifth of Australia’s uranium goes to the UK, but it cannot be used for military purposes, or sold to other countries who use it for their militaries.

Dr John Kalish, acting director general of the Australian Safeguards and Non-proliferation Office, says a new deal will have to be done with the UK to mirror the old one with the EU.

Under the old deal and the proposed one, the UK can only sell the uranium on to certain countries.

‘Retransfers can only be made to third parties that have a nuclear cooperation agreement with Australia,’ Dr Kalish told a parliamentary committee on Monday.

But Dr Kalish could not reveal which countries Australian uranium ends up in, citing ‘commercial in confidence’.

Liberal MP Andrew Wallace can’t understand why.

‘I’m just trying to work out why the Australian people can’t be informed what third party countries the UK might reassign or retransfer uranium that comes out of this country?’ he asked.

Dr Kalish said he could give the committee the names of the countries, but they would have to remain secret.

Meanwhile, Labor’s foreign affairs spokeswoman Penny Wong gave a speech to the Australian Institute of International Affairs on Monday, in which she called for Australia to take a greater role in banning nuclear weapons.

‘A Shorten Labor government will seek to muster wide international support, including from the states that possess nuclear weapons, for a ‘No First Use’ declaration,’ she said.

‘For states with nuclear weapons to adopt a ‘No First Use’ policy would constitute a major step forward in reducing tensions and risks of accidental or mistaken use.’

Senator Wong says Labor will also use Australia’s strong relationships with nuclear weapons states to push for a reduction in their nuclear stockpiles.

‘Dismantling 15,000 nuclear warheads and the security arrangements that rest upon them is not going to happen overnight,’ she said.