Grant Robertson has a tough job as Labour's finance spokesman. He has to critique National's performance without yet having formulated his party's own economic policy.
And when he does come up with a new economic policy, it has to be an alternative not just to National's but to Labour's, which was so roundly rejected by voters.
And he has to be seen as a credible alternative finance minister to Bill English without having had a finance background or run a business.
That won't be a problem, he says, pointing to the last Labour Finance Minister, historian Dr (now Sir) Michael Cullen, and the incumbent, who was a Treasury official.
"I think Michael and Bill are both examples of people who are seen to be good Finance Ministers who haven't had that background," he told the Herald."I think Annette King was a wonderful Health Minister but she wouldn't be very good as a heart surgeon."
Until he became an MP in 2008, Mr Robertson's credentials were in political management and communication as a senior backroom operator in Helen Clark's Government.
Labour leader Andrew Little offered him what you might call "second prize" after he came second in the November leadership contest, winning the majority of caucus and member support for his bid, but not the unions'.
Mr Robertson makes it clear there are several ways he will be different from his predecessor, David Parker.
He wants to cut down on the number of policies and focus on a few and he wants to humanise Labour's economic policy. That will mean less talk about poverty and the current account deficit, important as they are, and more talk about people and work.
"Labour is the party of work and workers and if we look at the perception of the party, it may be that we have lost that connection to work.
"We are not going to not talk about poverty, because we have to, but we want to be the party of work and workers."
To that end he is leading a major two-year exercise, the party's Future of Work Commission, involving non-party specialists and interest groups as well as members to come up with ideas in five areas: technology, security of work and income, education and training, Maori and Pasifika, and economic development and sustainability.
"There's a phrase that I like which is the concept of an economy with a human purpose," he said. "This is where perhaps I am different from other finance spokespeople, and not just ours.
"To me, the economy is only a means to an end to the kind of society we want, to the well-being of New Zealanders. I am much more interested in that shape of the economy.
"When people fill out surveys and say, 'The economy is the most important thing to me', they don't mean the trade-weighted index or the current account deficit. They mean, 'Do I have a job?' and, 'Am I being well paid to pay my bills and put some money aside and make sure the kids can have what they need?'
"I want us to be able to shift the debate a bit to being around 'how does the economy work to achieve those goals?"'
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Mr Robertson recently returned from a conference in Mexico of social democratic parties about "inclusive prosperity" - how to make capitalism work better for more than the wealthy. "I'll be looking at employment as a hugely important thing but I really will be looking at that concept of 'inclusive prosperity', of the fact that a wider group of people are getting opportunity and are seeing their well-being and their living standards lift."
His finance hero is Sir Michael, who spent nine years in charge of the purse-strings. "I do think Michael was a fantastically good Finance Minister in that he was able to manage the books carefully but to also create good social progress."
But Sir Michael had eight years as Labour's finance spokesman before becoming minister in 1999.
So would Mr Robertson be ready to become minister now, were it required? "Well I have to be, don't I? And yes, I would be ... but the longer I've got to run in, the better."
Does surplus matter?
A large minority of voters believe National's failure to reach surplus in the current year seriously dents its credibility.
But a majority believe it doesn't matter at all or it doesn't matter much.
Finance Minister Bill English confirmed on Friday that the Budget on May 21 will not show the Government's books going into surplus until the 2015-16 year because of the effects of low inflation and interest rates on Government revenue.
National has made it a top priority in the past two elections to get the books into surplus in the 2014-15 year, which ends on June 30.
The DigiPoll question was asked when it looked unlikely the Government would meet the target but it was not certain.
Of the 750 respondents, 36.7 per cent said it did not matter, 29.4 per cent believed it seriously dented National's credibility and 28.7 per cent thought it mattered but not so much because it was likely to get into surplus a year later.
Mr English has downplayed the missed target as being like a diet in which the goal is to lose 10kg but you lose only 9.8 kg, and said the discipline of having the target had constrained Government spending.
But Labour's finance spokesman, Grant Robertson, said it was a test National had set itself for economic credibility and it had failed.
He said National's failure in meeting the target more broadly reflected a failure to grow and diversify the economy.
•Labour finance spokesman for past five months.
•MP for Wellington Central since 2008.
•Former deputy leader to David Shearer.