The Law Society will wait until the bill is reported back later in the week before commenting on the changes.
Dr Harrison is joining other critics of the bill, including Kim Dotcom, to speak at a public meeting in Mt Albert tomorrow night, ahead of protests around the country against the bill on Saturday.
Dr Harrison said the changes to the bill essentially related to what Mr Dunne termed as "increased oversight, and a future "independent review of the operations and performance of the GCSB and NZSIS and their governing legislation".
"However, none of these measures addresses the substantive flaws in the GCSB Bill, which have been repeatedly pointed out to the Government during the select committee process. "
"Increased oversight after the event, whether real or ultimately illusory, cannot prevent excessive surveillance and gross abuses of individual privacy, if that is what the empowering legislation itself permits.
"Equally, periodic future review of the legislation is no comfort, if flawed legislation is to be permitted to operate in the meantime."
The prospect of Mr Dunne working on the issue of what constitutes ''private communications" could be of no consolation "if his vote alone now provides the necessary bare majority for the passage of rushed, ill-conceived and downright dangerous legislation."
The GCSB has been New Zealand's foreign intelligence agency. But the Government Communications Security Bureau and Related Legislation Bill will expand its legal powers to spy on New Zealanders through its cyber protection role and legalising the assistance it has been giving to three domestic agencies, the SIS, the Police and Defence.
That assistance will have to be declared under Mr Dunne's changes and Prime Minister John Key said this week he believed that it would involve no more 10 to 12 occasions a year.
Tech Liberty spokesman Thomas Beagle was one of many submissions on the bill with concerns about metadata and said it was still not clear what the GCSB was doing.
"Metadata and mass surveillance is what we are seeing all our allies doing - what we are seeing the Brits doing, what we are seeing the Americans doing and we can be pretty sure that the GCSB wants to be doing it too," he said on Radio New Zealand.
What it could not do should be in the bill at the very start.
Mr Key said this week that any collection of metadata had to be done under a warrant and there neither had been nor would be mass collection of metadata.
"There is no wholesale collection of metadata on some sort of fishing exercise that is currently undertaken by GCSB nor will there be in the future," he said.
"I have asked that question of the officials and the answer I have been given is that it is not a wholesale collection of metadata."
Mr Key said some people opposed the bill because were simply opposed to New Zealand's position in the Five Eyes intelligence alliance with Australia, USA, Britain and Canada.
"Anyone who has been around long enough in my role or as Foreign Minister or other roles would understand that there is huge benefit to New Zealand in the Five Eyes. The reality is that their capacity to give us information is far greater than our capacity to gather information on our own. "
"We are ...always careful of what our agencies do. We comply with the law and I don't believe our agencies are ever used to circumvent the law of countries we work alongside."
The Chief Human Rights Commissioner, David Rutherford, and the Privacy Commissioner, Marie Shroff, who both voiced concerns about the bill are still digesting the changes.
Peter Dunne's changes to the bill:
* An independent review in 2015 of both the GCSB, the foreign spy agency, and SIS, the domestic spy agency, and thereafter every five to seven years.
* The GCSB having to declare annually the number of times it has helped the SIS, Police and Defence Force use its specialised equipment.
* A requirement to notify the Inspector-General when a warrant to spy against a New Zealander is issued.
* A requirement by the GCSB to report annually on the number of warrants and access authorisations it has obtained.
* Ensuring that any expansion of the number of domestic agencies the GCSB can help with specialised equipment has to be made by Parliament, not the cabinet by regulation.
* Require the GCSB and the SIS to hold public hearings before the Intelligence and Security Committee for an annual financial review.
* Having the definition of the term ''private communications" and metadata reviewed to ensure the definition is updated and there is consistency across the GCSB law, the SIS law, and other relevant legislation such as the Crimes Act and the Search and Surveillance Act.
