When the economy was booming and the Government's coffers overflowing he banked the surpluses and took the political heat.
Now economic growth is at a standstill, the coffers are underflowing and he haspushed the fiscal accelerator to the limits of prudence.
"We have saved for a rainy day and can deliver relief when it is needed, without destabilising the economy." he said.
Budget surpluses shrink to less than 1 per cent of gross domestic product over each of the next four years. That compares with 3.5 and 3 per cent in the past couple of years.
It runs the risk they will turn into deficits, if economic growth and Government revenue turn out weaker than forecast - and forecasting is a very inexact science.
Dr Cullen is also prepared to run cash deficits of around $3.4 billion over each of the next four years, four times larger than expected six months ago.
"That's the limit of my comfort zone. Beyond that we are starting to borrow for the groceries," he said.
Government spending is set to increase by $4.5 billion or 7.8 per cent over the 2008/09 year while revenue will be flat. To cut back on public spending at this stage of the cycle would be procyclcial - exacerbating the economic downturn.
So by his lights Dr Cullen has done as much as he can to stimulate the economy, whose growth has pretty much ground to a standstill.
Now the onus is on Reserve Bank governor Alan Bollard.
