Budget 2019 eclipsed by allegations Treasury was hacked

The Budget has been totally eclipsed by allegations the Treasury was hacked, of National Party Budget leaks and with calls for the Finance Minister to resign.

Newshub understands National leader Simon Bridges is planning to reveal on Thursday - Budget day - how his party gained access to Budget details that were released on Tuesday.

Grant Robertson, the Finance Minister, will have to compete with the National leader on the day his Budget's released.

He'll also deal with the aftermath of police being called in by Treasury over alleged hacking which has far wider security implications, and National breaking details of the highly-secure Budget days early.

Bridges was furious on Wednesday that Robertson had linked National to allegations the Treasury was hacked. Bridges labelled the Government "bungling" and "incompetent" and "embarrassing".

But he saved his most descriptive language for the Finance Minister: "I say to Grant Robertson, you are lying, you have smeared the Opposition of New Zealand".

The Government hit back, with Robertson labelling Bridges a "desperate man".

When Robertson was told Bridges accused him of defaming the National Party, the Finance Minister replied: "That's ridiculous."

Deputy Prime Minister said Bridges would be "gone-burger" because of the ordeal.

After National released details of the Budget on Thursday, Treasury called in the police, claiming the information was hacked.

"The hack was the source of some of that information," Gabriel Makhlouf, Treasury Secretary and chief executive, said on Wednesday. He said the organisation's website "was attacked".

Makhlouf likened Treasury to a bolted room, and yet it was attacked 2000 times, with some of those attacks successful.

"Somebody has found a weakness in the bolt and has spent a long time working away at that bolt, not once twice, three or four times - we reckon at least 2000 times, and eventually that bolt broke."

Prime Minister Jacinda Ardern tried to tone it down, saying it's "a matter for the Treasury", and attempted to take the moral high ground: "If it were me, no, I wouldn't have done it, but for each of us our own judgment call."

But the Deputy Prime Minister didn't hold back. He said the figures National obtained "came to them in circumstances that were totally illegal".

Bridges insisted there had been "nothing illegal or even approaching that from the National Party at any time".

There's speculation the Budget details were hiding in plain sight, perhaps easy to access via stored web pages not yet published, or simply by changing the date on old Budget documents online from 2018 to 2019.

But Newshub understands it may have been even simpler than that.

When asked if something as simple as that could make Treasury look incompetent, Robertson said: "What Treasury said is 2000 attempts to enter their system."

He said he had "no idea" if it was the National Party.

The National leader said there had been "no hacking under any definition of that word".

Cyber-security experts are divided. Darkscope Cyber Security's Bruce Armstrong said the information was "was in a public space Treasury put in public space and someone has gone and found it".

Cyber-security lawyer Rick Shera said: "There could be crimes here both in terms of hacking but also in the act of receiving those digital files."

National deputy leader Paula Bennett called on Robertson in Parliament to resign when the hacking allegations "have been proven false".

Whatever the outcome, the Finance Minister's big day has been totally overshadowed.