"Today we are facing a Government we thought we could trust. Instead they are stripping away the freedoms and rights of everyday Kiwis."
He said he believed the Government didn't know what to do next and had run out of ideas.
He said he was not a scientist or politician. Some of those gathered "probably were experts by now because of everything they had read on social media", he said.
Auckland was coming up to spending 50 days in "home detention", Tamaki said.
"That's what they give to prisoners. We've all gone to prison."
"Society has been restructured in fear," he said.
Earlier this week Auckland Mayor Phil Goff slammed Tamaki as an "idiot", after revelations he was planning the protest.
"So many Aucklanders have worked so hard and sacrificed so much to try to get rid of this virus. These people seem to be working in the opposite direction. That's not good enough," Goff told Newstalk ZB.
Goff said he wished there was "some element of common sense" from Tamaki.
"Our police have got so many things that they need to be doing fighting crime, they don't need to be wasting their time dealing with idiots.
"We've seen it in the United States and we've seen it in Australia and Melbourne recently and we've all thought most of New Zealand is more sensible than that - they follow common sense and they're not extreme," Goff said.
Other speakers on stage today called on protesters to keep socially distanced as much as possible and to wear masks if they had them.
"This is a peaceful stand … all around the world we have seen all sorts of stands and some have been riots… but this is a peaceful stand," one of the MCs on stage has told those gathered.
Signs held aloft talk about pro-choice and freedom from lockdown and "freedom to be me".
Police kept a low profile on the edges of the protest. Security staff in high-visibility vests are flanking the stage and moving among the crowd.
Other users of the Domain - dog walkers, cyclists and joggers - all moved past the protest.
Rally protesters started to disperse about 12.15pm, after Tamaki finished talking.
Police earlier said they would be visible at the rally, which was organised by Destiny Church, and warned protesters could be arrested.
A police spokeswoman said officers would monitor the event, while reserving the right to arrest or fine those breaching Covid restrictions.
"Police will be monitoring the situation and responding accordingly," she said.
"Police recognise and respect people's lawful right to protest. However, under level 3 restrictions, the only gatherings allowed are weddings, funerals and tangihanga with no more than 10 people."
"Police do have the ability to take enforcement action, including issuing infringement notices, summonsing to court and making arrests, for those found to be breaching the restrictions currently in place."
Tamaki's rally got under way this morning in Auckland after he met top police bosses Andrew Coster and Wally Haumaha last week.
The three discussed health and safety measures for the rally.
"The three of us had a Zoom meeting and they recognise it is a part of the Bill of Rights for people to protest," Tamaki said at the time.
"We are trying to be responsible, and they said it is something they can't stop. We agreed to cooperate and we will make sure we are Covid responsible.
"Commissioner Coster asked for masks to be a condition, which I agreed to. It is a small compromise."
After the meeting, Coster wrote to Tamaki to summarise what was discussed.
Coster wrote while it was unusual for him to be involved in a discussion of that kind it reflected his concern about the level of interest in the gathering and its potential size.
"I do not wish to end up in the position that other jurisdictions have when policing protest activity, and prefer to take a preventative approach," he said.
"I note that the current health order requires that people do not leave their homes except for essential personal movement, which creates a risk to those attending this planned event. Police respects that protest is part of a free and well-functioning democracy.
"However, that must be weighed against the lawfulness and reasonableness of the protest activity. As we have indicated, gathering for a protest run other than in compliance with the law carries with it the risk of Covid transmission and may lead to enforcement action, including against yourself as an organiser," Coster said.
Coster told Tamaki he was concerned with the positioning of the protest and the particular use of the phrase "Let's get arrested".
"We would ask that you clarify your public messaging on this point, i.e. be clear that you intend to run this event safely, and that you do not intend people to act in a way that leads to their arrest."
Coster said that in continuing with the planned event, "you do risk an enforcement response by police".
The Auckland region is currently under alert level 3, which means movement is restricted to going to work, shopping or getting exercise. While some business travel is allowed, residents are required to stay within household bubbles and keep close to home.
Epidemiologist Michael Baker said it was a high-risk activity in the time of a pandemic at alert level 3 in Auckland, but wearing a mask at all times would minimise some risk.
"This opposes the need for physical distancing but an event outdoors is a lower risk of transmission unless it is a still day," he said.
"The real problem is going to be in Auckland, where it only takes one person who is infectious to potentially infect a lot of people.
"The difficulty is what happens before and after the protest like shared transport and socialising afterwards, especially indoors where most people don't wear masks inside."
High-profile businessman Leo Molloy - who is a close friend of the Tamakis - is expected to be one of the speakers.
Molloy said his speech would be about why Kiwis should get vaccinated.
"I will talk about the right to make an informed decision and to trust science," Molloy said.
"I'll talk about the responsibility leaders have in every sector, political, business, religion, sport, even gangs - every sector should have strong leaders who will preach the Bible about being vaccinated."