Greenpeace protesters remained camped on top of the Marsden B power station near Whangarei last night as police kept watch from the ground.
Four Greenpeace activists scaled a 50m-high wall in a bid to force the Government to stop plans to refire the mothballed station using coal.
The protesters had
enough food and water to stay for a "prolonged period", said campaigner Steve Abel.
They unfurled a banner reading "Save The Climate - Stop Coal", featuring an image of a burning Earth.
The protest was timed to coincide with the start yesterday of the Kyoto Protocol, which aims to slow global warming by reducing carbon dioxide emissions.
Most of the industrialised world, including New Zealand, has ratified the treaty.
From atop the power station, activist Kate Lowe said: "This would be the first coal-fired power station in New Zealand in 25 years, at a time when Kyoto has just come into force.
"Marsden B is a dirty, polluting power project, a climate killer and will leave a toxic legacy," she said.
"If the Government is serious about Kyoto, then it should stop this project now."
State-owned Mighty River Power, which is behind the Marsden B project, said it was concerned about safety at the site.
The roof was 20 years old and the site was "live" because the station helped to maintain the power supply to Auckland and Northland, said spokesman Neil Williams.
"We would urge those with concerns about our plans for the site to work through the appropriate submission process and stay within the law," he said.
Whangarei police Inspector Paul Dimery would not reveal whether he had plans to dislodge the protesters.
Public submissions on the proposal to convert the oil-fired power station close on February 24.
