Australia threatens Labour Party over citizenship scandal

Australia's Foreign Minister Julie Bishop says it would be "very difficult to build trust" with Labour if they form a government after September's election.

After speaking to an acquaintance in the Australian Labor Party (ALP), Chris Hipkins put two Parliamentary questions to Internal Affairs Minister Peter Dunne about the citizenship of children born in Australia to a New Zealand father. 

Mr Dunne then revealed Mr Joyce is a New Zealand citizen, meaning it's against the law for him to stand in office in Australia.

Having criticised the ALP over its contact with Labour MP Chris Hipkins, Ms Bishop was asked whether she would trust a future NZ Labour government.

"I would find it very difficult to build trust with members of a political party that had been used by the Australian Labor Party to seek to undermine the Australian government," she said in Canberra on Tuesday.

Mr Hipkins has caused a trans-Tasman political scandal with his questions. The whole affair has thrown the Australian government into chaos, after three politicians had to stand down when it was revealed they also held dual citizenship.

Mr Hipkins told media on Monday that he should have looked into the background of why his ALP acquaintance was seeking information, and said he had no intention of getting involved in Australia's politics. He said he never spoke to the ALP member about Mr Joyce specifically.

However Prime Minister Bill English says it's up to MPs to make sure they don't get embroiled in the politics of another country.

"I can't remember a time when an MP has done something like that that involves the politics of another country. It's just another misjudgement about what is actually a serious issue," Mr English told reporters.

The High Court will determine later this month if Mr Joyce is in breach of the Australian Constitution's prohibition on dual citizen MPs.

NZN / Newshub.