Chief Ombudsman Peter Boshier has warned MPs the sweeping executive powers granted to ministers under the new Fast-track Approvals Bill will require extra checks and balances written into the law.
In its current form, the bill would allow three ministers to green-light roads, dams and other projects, even if an expert panel advised against them and they had previously been denied consents by the courts.
In his submission to Parliament's Environment Select Committee on Friday, Boshier said the bill should explicitly state that the panel was subject to the Ombudsman Act and Official Information requests.
Responding to a question from Labour MP Glenn Bennett about the risk and if it was not made clear, Boshier said government ministers were already struggling to comply with the Official Information Act due to their workload.
"Ministers will be flooded with requests for information instead of those going by direct route to the panel. In the end it makes it more complicated, more wordy and more prolix."
It was vital that the expert panel be subject to the same oversight as other government agencies, Boshier said.
"New Zealanders must get the opportunity to consider the evidence given to ministers."
In April, the government was forced to release the list of organisations invited to apply to have their projects fast-tracked after Forest and Bird made an official complaint to the Ombudsman's office.
In a move labelled "cynical", the list included organisations that have lost cases in the Environment, High and Supreme Courts, after prolonged court action.
However, Infrastructure Minister Chris Bishop finally released the names just hours before submissions on the bill were due to close on 19 April.
Boshier said the ombudsman did not have the power to make inquiries into the use of executive power, although the courts had "some jurisdiction, though limited".
Green MP Lan Pham, a freshwater ecologist and former regional councillor for Canterbury, asked the ombudsman what the risk would be if there were insufficient checks and balances.
Boshier said unchecked executive powers could put the country on "a slippery slope".
"On the one hand, I can see why speed achieves what's wanted with a beefing up of executive power, but unless that's matched by oversight and accountability, then I think democracy itself is the loser."