It might not be there. The Budget's political narrative will be that the previous Government's surplus was built on "years of neglect" of hospitals and schools and a failure to ensure public infrastructure kept pace with rapid population growth. It is also facing pressure for high public sector pay rises, particularly from nurses' and teachers' unions.
But Labour campaigned on a platform of fiscal responsibility at the election last year, promising to keep the Budget in surplus and reduce net Crown debt at only a slightly lower rate than National had planned. It is important that it keeps that promise. Low net government debt is the country's insurance against the next economic downtown, enabling deficits to be run when they are needed.
A healthy surplus in good times such as this is also important for business confidence in the new Government. Labour and National will argue long and hard about whether the surplus National has bequeathed was built on "underfunded" needs and capital neglect and public opinion will be divided along political lines. But if those who invest money in business expansion and job creation do not see fiscal responsibility in the country's economic management, they will be reluctant to risk more of their money.
The Government has inherited public accounts that are healthy enough to enable it to increase spending without sacrificing the surplus. Nevertheless, it needs to be spending wisely.
Budget speeches are festooned with additional sums of money being proudly spent on health, education and other social goods. It can seem the only measure of virtue is the size of the allocation. It is not so. We need to know precisely what services will be purchased, how they will be effective, and how the Government proposes to measure their results.
We do not really know a government's character until we see its first Budget. We will know this one better tonight.