"It's going to take us a bit of time."
Robertson is set to undertake a series of speeches to mainly business audiences over the next two weeks in a bid to arrest declining business confidence.
Robertson described the Budget as "the first steps of our plan to make our economy and communities stronger, more productive, more sustainable and more inclusive."
National leader Simon Bridges has said Labour will spend more and borrow more – and that much has already been foreshadowed by Labour.
In the Robertson's pre-Budget plan in December, he earmarked additional borrowing of $10 billion as well as spending of $2.6 billion in operating spending for Government services (compared to National's plan of $1.7 billion) and $3.4 billion in capital spending on building and infrastructure (compared to National's $2 billion).
Since then, the Government has received windfall gains of about $900 million in extra revenue, and from $700 million cuts to existing programmes and policies over four years.
But with EQC's disaster fund on track to be depleted by early next year, and the growing compensation costs of making farmers kill dairy herds infected with M. Bovis, there is no end of demand for the extra dollar.
The forecast surplus of $2.8 billion and GDP growth of 2.9 per cent are likely to revised upwards.
The Budget will allow Labour to shift the political focus on a state house building programme which will augment its Kiwibuild programme for lower-cost private homes, and its recent $100 million package on emergency housing for the homeless.
State house waiting lists are at 7890 and with Ardern imploring people in need to put themselves on the list, demand is likely to grow.
Bridges said any Government worth its salt would be spending more in education and health, as the previous Government had.
National had left the legacy of a strong economy.
"We can expect to see more taxing, more borrowing, more spending and a bit more of hoping, actually, from them."
Deputy Prime Minister and New Zealand First Prime Minister Winston Peters, who has already received a bountiful boost of $900 million for Foreign Affairs, said his party's influence would be evident in it.
""It will have a whole new look of a budget that's got a heart and a conscience," he said.
"That's what makes New Zealand First special in this Government."
Revisiting a theme from the speech he gave when choosing Labour in October to lead the Government, Peters said: "We are going to see capitalism regain its human face."