Jacinda Ardern arrives back today from her hugely successful and unique mission to Paris firmly focused on domestic challenges in the month ahead.
We will see some of them publicly enough such as the teacher strike the day before the May 30 Budget.
But some of the biggest challenge are less visible and involve strains within the Government.
They are invariably about constraints: what constraints one party is placing on the plans of another; and constraints of voice – how much each party must limit what it says to avoid disunity.
And because they involve Labour's partners, New Zealand First and the Green Party, they must be handled with kid gloves by Ardern.
Shane Jones has clearly had the hard word from the Ninth Floor of the Beehive to constrain himself because he is trying very hard to keep himself out of trouble – with mixed success.
Jones, New Zealand First's Regional Economic Development Minister, is super sensitive to criticism over the $3 billion provincial growth fund. But so is Labour.
Any suggestion the fund is being administered sloppily reflects as badly on Labour as it does on New Zealand First.
There has been a concerted effort to improve his presentation of the fund.
So Jones hosted a media briefing this week with leading officials as if to say, if you don't believe me, listen to them.
The trouble is that Jones seems unable to distinguish between legitimate questions about the massive spend and political attacks on the fund.
It is not only the news media and the Opposition asking questions, it is the Auditor-General as well.
While not investigating any allegations of impropriety, the AG is concerned to see that there are proper processes for allocation and monitoring of such a large fund, established so quickly after the Government was formed.
One of the things we were told at the briefing is that the method of evaluating the various projects is still under development.
It is not the handling of the funds that is the problem, however. It is Jones' messaging. He goes onto war footing every time he is asked about it.
Were he to simply acknowledge questions as being perfectly legitimate and answer them without responding as though every question were a personal insult, he would be doing a better job for the Government.
His antics have definitely helped give New Zealand First profile in the regions but it has been at the expense of smooth relationship with Ardern. He repeatedly plays the victim, and one day he might find that he is.
Ardern's most recent reprimand was over his call to the New Zealand Transport Agency to ask a legal question related to its prosecution of a transport company on health and safety grounds.
As Jones himself has said when acknowledging the telling-off he from her, she is entitled to reprimand him, but his first duty will continue to be New Zealand First leader Winston Peters and the so-called party of the provinces.
The plan to win rural support went slightly awry this week when Jones decided to rip into Federated Farmers on Country radio over their opposition to the biogenic methane targets, then lambasted all farmers as moaners.
Despite that outburst, the fact that Jones has been constrained was very clear this week in his muted response in the Herald to the actions of Green Party Minister Eugenie Sage in declining an application that will affect 350 mining jobs in Waihi.
As Land Information Minister, Sage has a veto on any sale in the category of sensitive land applications which, under directions of this Government, is any non-urban land over 5ha.
The OceanaGold company wanted to buy two farms for a tailings site to expand the company after 2028. Without it, the mine will close and most of the 350 jobs will go.
It is within the mandate of the Resource Management Act to decide whether the design would be up to scratch.
But Sage made herself judge and executioner by deeming something yet to be designed would be unacceptable, that gold mining is not a sustainable industry and therefore the sale would be no economic benefit to Waihi.
Jones would normally be shouting in full-cry about the decision, and its impact on the regional economy. He simply said it was within her statutory powers to do so and she knew what he thought.
Certainly Jones was among the ministers who sought to change Sage's mind behind the scenes - as did Associate Finance Minister David Clark.
The decision creates major problems for Ardern and Labour.
The idea that an MP from a party with 6.3 per cent of the vote can effectively decide when mining in Waihi should stop with the flick of her pen is wrong.
It may be lawful. But it cannot be defended morally.
Waihi has been synonymous with mining since gold was first found there in 1878. Sage, with the most audacious misuse of her statutory ministerial power, has called time by saying mining is not sustainable.
Locals are demanding to know what Labour and New Zealand First think about it.
Peters this week hid behind sub-judice when asked about it on Monday, although no application for judicial review had been filed.
Ardern herself may hide behind legal process. But if anything is not sustainable, it is the possibility that Ardern and Peters do or say nothing about the Waihi decision.
There are similarities and differences with the Government's ban on new offshore oil and gas exploration which was sprung on New Zealand.
While the process was fast, and went against the advice of officials because too little was known about its impacts, at least it was approved by the Cabinet.
It was approved by parties that have a majority of the Parliament.
The Eugenie Sage decision is opposed by parties with at least 110 of 120 seats in the Parliament.
All Green ministers are under pressure from their activist core to get more gains. They see compromise as failure, not the art of the possible.
Sage is playing God with people's livelihoods and there is no suggestion she won't continue to apply the same unorthodox minority judgements to future decisions.
She is presenting a big challenge to Ardern's expectations of how ministers should behave.