It's different for Bill English. He and his team are the Government. Every concession they make is something they must give up. That applies to ministerial places and policy positions.
In nine years in Government National never shared Cabinet. Its partners have only provided ministers-outside-Cabinet. It will be a major concession for National to make way for NZ First. National will have to learn to share power.
That's not a problem for Ardern. A successful deal will put her team into Cabinet, not kick some members out.
That advantage is a big one.
It's also easier policy-wise for Labour. National by philosophy is more stingy with taxpayers' money. It also thinks Government should do less, not more.
Labour enjoys a more expansive view of Government, which gives greater freedom in negotiations - spending more money and making bigger Government is not a hurdle. Shifting Auckland's port north won't be a problem for Labour; it will be a very big one for National.
Whatever deal English strikes, he will be criticised by his party, the media and the public as giving away too much.
He will look weak.
Whatever deal Ardern strikes, she will be seen as a winner, a genius negotiator pulling a win out of defeat. Her team will love her for it and so, too, her supporters.
Much is made of a three-way coalition with Labour, NZ First and the Greens being problematic compared to a two-way with National and NZ First. I don't see it.
The Greens have no bargaining power. Their refusal to go along with whatever is offered by Labour and New Zealand First would simply put National in power, or be cause for another election. Neither option is an attractive prospect for them or their supporters.
Ardern can offer the Greens a couple of ministerial posts outside Cabinet and a couple of policy wins, and that's it. That's better for them than another three years in Opposition.
The Greens have little option but to accept the offer and will appreciate finally being in power, albeit in a lesser role than hoped.
Ardern's negotiating strategy with Peters is simple: "I really, really want this to work. What will it take?"
