UPDATED 5.58PM The Government’s books are well and truly in the black, with the Crown’s end of year accounts more than a billion dollars healthier than expected.

In May’s Budget the Government was forecasting a financial year surplus of $668 million.

However final figures released today put the surplus at $1.8 billion, a $1.4 billion improvement on last year.

Factors include a more than four percent increase in economic growth, an almost six percent increase in tax revenue, and a lower than expected increase in core Crown expenses.

Finance Minister Bill English said Government surpluses are rising and debt is falling, and puts the Government in a position to be able to make some real choices for New Zealand.

He said if there’s further fiscal headroom the Government may have the opportunity to reduce debt faster, and if conditions allow they will begin to reduce income taxes.

But will tax relief happen in election year? Mr English isn't giving a conclusive answer.

"Well that's yet to be decided. You'll have to wait and see just how the Government approaches it."

In a press conference this afternoon, Mr English said there will be an increase in capital investment by the Government, peaking next year.

He said increasing prison capacity would be among the projects.

"There will be a need for more capacity. There's work going on about how exactly you would do that - whether it's across the existing prison system."

However, the Government surplus is being dismissed as just another sign of mismanagement by the Greens.

Green co-leader James Shaw said the Government should actually be running a balanced budget.

"Look, I mean a surplus actually ends up being inefficient - you're actually taking money out of the economy, and so the idea is you want to run a budget that is close to balanced as possible."

Labour's finance spokesman Grant Robertson said this is no time for the Government to be celebrating.

"It is all well and good to be pleased about a surplus, but when there are children living in cars and garages, older New Zealanders in pain waiting for an operation, and school funding going backwards, the government needs to take a long hard look at its priorities," he said.

Also revealed in the annual Crown account figures today - the cost of the country’s Cabinet Ministers is on the rise.

They show the total cost of personnel expenses for the Government’s 28 ministers was more than $21.7 million in the last financial year.

That’s an increase of almost $640,000.

However, on the plus side, the increase did come in at $20,000 less than what had been budgeted for.