Will the Government borrow money to buy old borrowing?

Finance Minister Grant Robertson arriving for his 2020 Half Year Economic and Fiscal Update Photo / Mark Mitchell

The Government could be about to issue more debt, so that it can buy old debt from itself.

Or it could use some of the money raised by debt the it has already raised to purchase the old debt.

It all sounds very confusing - and in part it is.

It is not fiscal chicanery - it is simply the latest phase in the monetary tactics governments and central banks have used worldwide to prop-up Covid-ravaged economies.

During the pandemic, New Zealand's Reserve Bank did what many central banks around the world had been doing for a decade and began printing digital money to pump into the parched economy.

The bank got money into the economy by buying up vast quantities of government debt from banks and other financial institutions in a programme called LSAP - Large Scale Asset Purchases.

The bank did all this because it wanted to reduce interest rates; the more money it printed, the lower rates would go - and the bank wanted those rates to be very low last year, to get people spending and shepherd the economy through the pandemic.

But now the bank wants to cut back on that monetary support. It has hiked the official cash rate twice, and plans several more hikes next year.

One of the next parts of withdrawing that monetary support could be offloading some of the $53 billion worth of government debt it has bought.

This puts the ball in the court of Finance Minister Grant Robertson.

A proviso in the agreement that let the bank buy all that debt in the first place stipulated that if the bank ever wanted to sell its holdings, it could only sell the debt back to the Government.

That means Robertson has to forge some sort of agreement with the Reserve Bank about how the bank might offload the debt.

Robertson told media on Tuesday that Treasury would have "something to say" about the strategy for reducing the Bank's bond holdings soon, possibly at next week's Half-Year Economic and Fiscal Update.

Robertson said the "tension" of respecting the bank's independence was a part of the wider LSAP discussion, but did not say how it would impact what the Government would decide to do.

"We are somewhat different to other central banks in that the Reserve Bank appears on the overall Crown balance sheet and therefore that particular tension is just built into our system," Robertson said.

There are two obvious sources of cash the Government could use to buy back debt from the Reserve Bank: the first is using the billions of dollars of cash it has in its settlement account at the bank itself.

The second is by issuing more debt to buy back the old debt.

Finance Minister Grant Robertson arriving for his 2020 Half Year Economic and Fiscal Update Photo / Mark Mitchell

Robertson said what the Government decided to do would depend on how the bank wanted to reduce its debt holdings.

"A lot of this will depend on the discussions of how the Reserve Bank wants to do this, bear in mind they've indicated they're heading in that direction but the way in which they do it will impact on the way in which we respond," said Robertson.