Ratings agency Standard & Poor’s has reaffirmed Australia’s AAA credit rating and negative outlook.

The rating and outlook is the same as at budget time in May and follows the mid-year economic and fiscal outlook delivered by Treasurer Scott Morrison in December.

“Together with Australia’s AAA rating from Fitch and Moody’s, this means Australia continues to be one of only 10 countries that have maintained a AAA credit rating with all three major ratings agencies,” Mr Morrison said in a statement on Thursday.

S&P said in its update the negative outlook reflected “risks to the government’s fiscal consolidation plan and risks to financial stability, economic outlook, and fiscal performance, should home prices fall abruptly with negative consequences for financial stability”.

Mr Morrison said Labor’s “obstructionism” in parliament was frustrating further budget repair.

However, shadow treasurer Chris Bowen said the ratings agency had rightly highlighted concerns with financial stability and the need to rebuild the fiscal buffer.

“These are all things that Morrison is happy enough to ignore or attack Labor for addressing with its housing affordability and savings policies,” Mr Bowen said.

“Federal Labor opposes Scott Morrison’s irresponsible $65 billion big business tax cut, which is the single biggest hit to the budget over the medium term, while also putting forward reforms to negative gearing, capital gains tax and trusts.”

S&P said the negative outlook reflected the “significant uncertainty” around the ability of the federal budget to return to surplus by the early 2020s.

“We could lower our ratings if within the next year or so we come to the view that the government’s fiscal consolidation measures are insufficient to achieve that target,” it said.

“The ratings could stabilise if the government were to demonstrate its ability to achieve a significant and sustained improvement in the medium-term budget outlook, leading to a return to a general government surplus.”

It would also require “sustained moderation of credit growth and home prices”.

Enacting further savings or revenue policies could remain a challenge given the Senate’s unwillingness to legislate, or delay in passing, government measures, the agency said.