"This is short-term thinking and it doesn't make sense. We must invest in and value institutional knowledge."
While in Opposition, National was highly critical of Labour's failure to keep consultancy fees under control.
Finance Minister Bill English said the contractors had been employed for work which the public service had neither the funding nor the expertise to do.
He said specialist skills were needed for the rebuild of Christchurch, the design of the Deposit Guarantee Scheme, and on multi-billion dollar IT projects.
"We just don't have public servants sitting around who know how to redo the 25 year-old tax collection system," he said.
Mr English said the previous Government ran down the technological level of the public service to a "disgraceful level" and it had cost billions to rebuild it.
There were still many large-scale technological projects to be completed so the increased spending on contractors would continue for several years.
Departments which had undergone major restructures had incurred the largest contracting fees, such as Corrections and Defence Force.
The merging of several agencies into the Ministry of Business, Innovation and Employment (MoBIE) had cost $12.4 million in payouts and $104.5 million in contracting fees.