Heather du Plessis-Allan: Robertson is the ace in the pack

Finance Minister Grant Robertson has pulled a rabbit out of a hat with his infrastructure spending announcement. Photo / Mark Mitchell

Jacinda Ardern might have been Labour's hero at the last election, but if they win the government benches this time around it'll be largely thanks to Grant Robertson.

The Finance Minister has just pulled a trick that might be enough to save Labour from two years of poor performance.

Forget all the failures. Forget KiwiBuild and the Year of Delivery that delivered almost nothing. Forget the Most Transparent Government that is really as opaque as a glass of milk. Forget the PM completely fluffing her handling of the sex assault allegations. None of that will matter if Labour can do just one thing right: get these roads built.

With Robertson in charge that's entirely possible.

Robertson's played this week's infrastructure announcement like a symphony. He's mostly got everything right. He teased out the announcement for maximum positive coverage. First, he let us know there was $12 billion coming. That got good headlines. Then he announced the projects. More good headlines. And then he only spent $8 billion. That means he kept at least $4 billion in the kitty for another round (or even rounds) of project announcements. Expect more good headlines.

He's snookered National and its plans to go hard on roads at the election. It was obvious that was the game plan from all the billboards National had erected up and down the country reminding commuters that their planned roads had been binned by the Coalition Government. As of this week the opposite is true. The roads are back.

No one cares if Labour stole National's ideas. Mostly, no one cares if Labour wasted two years. What matters much more is what Labour now will do, and if Labour can prove it'll deliver these roads, that's enough for voters.

But can Labour deliver? That'll be their biggest test. They've got eight months to get shovels in the ground or they're stuffed. KiwiBuild was a great idea but they didn't pull it off and it blew up in their faces. But then, Phil Twyford was in charge of that. Twyford might be Transport Minister but he's not in charge of this. Robertson is. All the ministers involved in this infrastructure plan report to Robertson. He's clearly not taking any chances on some other schmuck stuffing this up, which shows you Labour knows how important this is to re-election.

Jacinda Ardern was the star turn at the last election. Photo / Mark Mitchell

Robertson is one of the safest pairs of hands in this Government. He's hardworking, intelligent and immensely likeable. He stood for the Labour leadership in 2014, lost by a hair's breadth to Andrew Little thanks to Little's union backing, and then graciously sucked it up publicly. He put his hand up for the opposition finance job, hit the books, got to know the detail and has proved himself to be as conservative as you'd expect from a Labour finance minister trying to disprove the old tax-and-spend tag.

Robertson deserves a lot more credit than he gets from the wider public. He's kept a reasonably low profile most of this term. It might be deliberate because he believes Ardern is the government's real star. It might also be inadvertent because he's too busy working.

But he might just be as much of a star as Ardern. While she is often called one of the most gifted communicators of her generation, he is not too bad at that himself. In some ways Robertson actually performs better. Under pressure, he's unflappable. Where Ardern has a tendency to condescension, Robertson is measured and rational. Where she occasionally takes the bait and sounds piqued, he is unfailingly polite.

It's often the case that the star PM has a details guy backing them up. John Key had his Bill English. David Lange had his Roger Douglas. And so, Jacinda Ardern has her Grant Robertson.

But he might just be the details guy worth trotting out publicly a bit more often.