"I understand that the climber intends to stay as long as it takes to ensure the safety of our taonga."
The group said the protest was a last-ditch effort.
It hoped the developer would resume mediation and honour a promise so a sale could be negotiated in good faith.
Ms Bonar said Waitakere councillor and deputy mayor Penny Hulse supported the granting for the resource consent permitting the tree to be felled on a non-notified basis. She said the group urged Ms Hulse to change her stance.
She said more than 40,000 New Zealanders had voiced their concern about the consent through Facebook and an online petition.
"The Paturoa kauri is a beacon of light and hope for all trees in our environment," Ms Bonar said.
She said she wanted to try all feasible avenues to avoid setting a precedent of "death by a thousand cuts" in the Waitakeres.
Former Prime Minister Helen Clark has posted a message in support of the protest on the Save Our Kauri community Facebook page.
"Appalled to think that this tree is still under threat!!" she said.
"Keep up the strong community advocacy!"
Mr Smith said he would be up the tree until the situation was resolved and had no idea how long that might be.
"I'm set for the long haul."
He'd set up a good camp and had food, water, ropes and sleeping gear.
Mr Smith said he'd been an arborist for 14 years. He'd witnessed "quite a few big trees" coming down and said he needed to take a stand and make sure this one didn't.
Supporters had been coming and going from the site all morning, he said.
Helen Clark's message of support from overseas had given the community a boost.
Mr Smith said the landowner had gone back on his promise not to remove the tree. The local community rallied together well to stop any trees from getting felled after contractors arrived on site yesterday.
He believed members of the community were trying to get in touch with the landowner but to his knowledge hadn't made contact yet.
The kauri tree occupation isn't Mr Smith's first protest.
He recently climbed Parliament buildings with Greenpeace and installed solar panels to encourage the Government to stop investing in fossil fuels and start putting money into the clean energy sector.
Labour MP David Cunliffe was this afternoon on his way to the protest.
"As the MP for Titirangi I think this is an iconic tree, I support the community group that's trying to save it and I call on Mr Lenihan to return to the discussions with council to find a compromise."
He believed it was possible for Mr Lenihan to adjust his building plans to save the tree.
"I think he should be in no doubt about the strength of community feeling on this issue," Mr Cunliffe said.
In March Mr Cunliffe offered to support the protest by joining Mr Tavares in the tree but he said he would make no such offer this time around.
"You know, I had a good look at that tree and I think it's probably beyond my climbing skill, that's the honest truth, but nonetheless they have my full support."
