Ms Harris also believed requiring lobbyists to register under law could give them a status or pre-eminent standing in policymaking processes.
"Such standing might be desirable in larger democracies, where the size of the body politic means not all who wish to participate in parliamentary processes can do so," she said. "This is not the case in New Zealand."
The Lobbying Disclosure Bill sponsored by Green MP Holly Walker won the unanimous support of the House to get past its first reading and to a committee.
And while most submitters endorsed the principle of greater transparency in decision-making, most also pointed to major flaws.
The bill requires disclosure of lobbying activities aimed at MPs and their staff, though staff of Crown agencies are exempted, and it requires the Auditor-General to develop a lobbyists code of conduct and register.
Ms Harris said the bill as worded meant she and her staff were not exempted. She suggested the bill might be better limited to the decision-making processes of ministers rather than all MPs.
She also questioned the Auditor-General developing lobbying codes in light of her "existing constitutional relationships with members, ministers and the House and her role in auditing the public sector".