Prime Minister John Key continues to take an optimistic view about New Zealand's credit downgrades, saying they are unlikely to spark mortgage rate rises.

International credit rating agencies Standard & Poor's and Fitch downgraded New Zealand last Friday, citing debt levels as a concern.

Labour leader Phil Goff said today the downgrades would be a wake-up call for many and that they had real implications for New Zealanders.

"It means that our mortgages are going to go up, it's going to cost more to pay for the mortgage on your home, and it means the cost of the Government's boring, and there's been a hell of a lot of that, will go up. That will cost us as taxpayers."


However, Prime Minister John Key said bank economists did not think the downgrades would result in mortgage rates increases.

"They're saying overall the situation is that, because we're such a good credit and because this is wholesale around the world, S&P have downgraded about eight or nine countries already, they think we'll actually attract capital, so [mortgage rate rises are] unlikely in the short term."

Mr Key said it was important to look at what the rating agencies were saying.

"They're saying it's a very weak international environment, they're not quite sure how that's going to play out, and they think that New Zealand has high levels of net external liabilities when it comes to the private sector."

Mr Key said Moody's, the other major international rating agency, did not consider the private sector component, which was one of the reasons it had maintained its rating.

The rating agencies were concerned about the uncertainty of the international environment, and what affect it could have on New Zealand's private sector, Mr Key said.

"What they're also saying though is that the Government actually is pretty much on the right track."

Mr Key said Standard and Poor's liked the Government's plans to get back into surplus, including changes to KiwiSaver.


In a statement following the downgrade, Standard and Poor's sovereign credit analyst Kyran Curry said: "We also consider the strength in the government finances to be an important mitigating factor to the risks associated with the external position."