Finance Minister Bill English has been forced to defend the Government's intention to allow the Transport Agency borrow large sums of money to pay for new roads.
Until now, roads have been built using money collected from fuel taxes and registration fees.
The Land Transport Management Amendment Bill tabled in Parliament on Tuesday would allow the Transport Agency to borrow to build new roads, subject to the agreement of the Transport and Finance ministers.
During Question Time in Parliament on Wednesday, Green Party co-leader Russel Norman criticised the Government for intending to borrow money for new roads when it argued that it was selling shares in state-owned energy companies to avoid borrowing.
Mr English dismissed Dr Norman's criticism, saying he can still stop the agency from borrowing money.