By Peter Wilson*

Analysis - Trench warfare in Parliament as Winston Peters and the Prime Minister dig in, Jami-Lee Ross is revealed as one of the men charged over National's donations and Simon Bridges confirms he'll fight the election on tax cuts. It's been a week of many questions and very few answers.

Photo: RNZ

The Serious Fraud Office's announcement that it will hold an inquiry into the New Zealand First Foundation and the uproar over a covert photo of journalists gave the opposition plenty of ammunition, but finding targets was the problem.

Prime Minister Jacinda Ardern's tactic was to stand aside from the controversy engulfing her coalition partner, ignoring demands that she stand down her deputy Winston Peters.

Peters, while appearing supremely confident that the SFO will clear the foundation, distanced himself from it and claimed to know little about it. At one encounter with the press gallery reporters he played Radio Gaga on his cellphone before walking away.

He has previously said it's nothing to do with him and he has never seen its accounts. National doesn't accept that, and deputy leader Paula Bennett accused him of trying to dance on the head of a pin.

Peters' line is that neither he nor his party are being investigated, so there's no conceivable reason why he should stand down. National says the connection with the foundation, which accepts donations and bankrolls the party through loans, is clear.

The SFO inquiry is about whether the donations should have been passed to the party, which would have brought them under disclosure laws.

The Electoral Commission holds the view that the donations should have gone to the party. It gave its file to the police who sent it on to the SFO.

How much Peters really knows is a matter of considerable speculation, but RNZ has documents which show he was present at a March 2017 meeting when the party's board agreed to the concept of establishing the foundation.

When the photo of RNZ journalist Guyon Espiner and Stuff's Matt Shand meeting former NZ First president Lester Gray first appeared on a right-wing website, Peters said "we took it to show the sort of behaviour that's going on" and then changed his story, saying a supporter took it simply out of interest.

National believes his first response was the valid one, and used it this week to demand a response from Ardern.

On Morning Report National's leader Simon Bridges cited "unethical behaviour, a complete inability and lack of desire to answer basic questions about things that, at the start of the year, the prime minister was quite clear were bad and dirty politics".

Ardern, he said, had adopted a "hear no evil, see no evil" position.

The prime minister faced a barrage of questions at her post-cabinet press conference, and maintained her stance that the SFO should be left to get on with its job, reporters were wrongly asking her to be judge and jury on the case, and it was entirely a matter for NZ First. As the questioners charged on, she simply told them: "I have made my position on this clear".

Staying out of it is really the only option she has. Criticising Peters could destabilise the coalition, taking action against him almost certainly would.

All the signs are that Peters and Ardern are going to tough it out. They know that unless there are dramatic new developments reporters will tire of asking questions which aren't answered and opposition MPs will find other ways to attack the government

On Wednesday the focus shifted sharply to National's own donations problems. Name suppression was lifted on the four men charged in connection with two donations of $100,000 which were broken down into smaller amounts so the donors didn't have to be identified.

One of them was Jami-Lee Ross, the MP who blew the whistle and tried to bring down Mr Bridges by blaming him for it. The New Zealand Herald described it as "the most spectacular own goal in political history".

Ross reacted by claiming the charges against him were outrageous, he had been set up as a scapegoat for the National Party, and he would deliver evidence in court to prove what really happened.

The other three men charged by the SFO were also named - the donors, Yikun Zhang, Shijia Zheng and Hengita Zheng. They said in a joint statement through their lawyers that they would defend the charges. "They were urged to follow a process and are now deeply disappointed at being caught up in a donations fiasco," the statement said.

Bridges is doing his best to shrug it off, saying the party is in the clear, but he must be worried about what could come out when Ross takes the stand. That, however, could be months away. The four accused are due to make their first court appearance on Tuesday.

Although there was heavy traffic in the way, National chose this week to announce tax cuts would be at the centre of its election campaign. Bridges is selling the policy as a way of easing the burden on taxpayers imposed by the government.

On his calculations people are about $4000 a year worse off than they were before the election, although that includes the government's repeal of tax cuts that had been passed by Parliament but had not taken effect.

Bridges said the aim was to help "average wage earners" but apart from that there were no details. Some glimmers emerged when National's finance spokesman, Paul Goldsmith, was interviewed on morning report.

"The average wage is around $64,000, it's been rising steadily over the past few years and somebody on that wage is not wealthy, they're struggling to get by," he said.

"What we're signalling is that… we'll be offering some tax relief."

Will the government meet the challenge? Ardern said Labour had not yet worked up its policy.

*Peter Wilson is a life member of Parliament's press gallery, 22 years as NZPA's political editor and seven as parliamentary bureau chief for NZ Newswire.