National is accusing the Government of mismanaging the economy as mortgage rates rise.
It comes after New Zealand's high inflation rate of 6.9 percent forced the Reserve Bank to increase the official cash rate (OCR).
The Reserve Bank on Wednesday raised the OCR to two percent, up 50 basis points, to take the cash rate to its highest point since mid-2016 which means mortgage rates will rise.
On Sunday, National Housing spokesperson Chris Bishop said Kiwis are facing paying thousands of dollars more on their mortgages every year.
"The latest analysis from the Reserve Bank will make for chilling reading for mortgage holders, with the central bank predicting the interest rate on one and two-year mortgages will hit 6 percent next year," Bishop said.
"This will mean a major hit for Kiwi budgets. A household that has borrowed $700,000 would face annual interest costs of $42,000, meaning they would have to pay more than $800 a week before they even begin to reduce the actual loan."
Bishop said the mortgage rate increases will hit new homeowners the hardest.
"The pressure will be especially great for those who have recently entered the property market, with the Reserve Bank acknowledging that many first time buyers from 2021 will find it difficult to pay their mortgages and cover their other expenses," he said.
"Kiwis are already paying more to cover their loans than they have in a long time. According to the Reserve Bank, the share of disposable income required to service a new mortgage is approaching 60 percent, the highest it has been, since before the Global Financial Crisis, under the [Helen] Clark Government."
He said the Reserve Bank and Government should be working in tandem to control inflation, not against each other.
"At a time when Kiwis are dealing with soaring inflation and rising interest rates, the Labour Government has announced the largest ever spending spree in the 2022 Budget," Bishop said.
"While the Reserve Bank is forced to apply the brake to the New Zealand economy, Labour is working against it. Governor Adrian Orr confirmed to MPs this week that the "very high" level of Government spending is putting upward pressure on inflation.
"Grant Robertson's spending addiction is contributing to higher interest rates, and the cost is being borne by households.
"In the face of rising costs and sharply rising interest rates, households are being asked to tighten their belts. At a time when inflation is at a 30-year high, the Government should do the same."
Finance Minister Grant Robertson denied Government spending is to blame, instead pointing to high demand for goods and services and global inflation.
It's a view that is shared by Reserve Bank Governor Adrian Orr, who told AM's Ryan Bridge on Thursday blaming Government spending for inflation was "too simplistic" and incorrect.
"I think that's far too simplistic and in fact wrong in a sense," Orr said when asked whether his job was made harder by the Government's spending.
"Government fiscal policies are both about long term infrastructure and all of the challenges, it is about making sure the current level of services can be supplied.
Several countries around the world are also experiencing high inflation rates as they begin their recovery from the COVID-19 pandemic.
The United States is currently at 8.3 percent, the United Kingdom is at 9 percent, and the Netherlands is at 11.9 percent, according to Statistics New Zealand. Meanwhile, Australia sits at 5.1 percent.
