Minister of Energy and Resources, Simon Bridges, on Wednesday announced the annual 2014 block offer for oil and gas exploration, which covers more than 400,000sq km.
The 2014 offer is twice the size of last year's.
The largest swathe is the combined offshore Great South Basin and Canterbury Basin areas, almost 142,000sq km.
Forest & Bird advocacy manager Kevin Hackwell said the block offer covered more than 925,200ha of land, and more than 39 million ha of ocean.
The onshore blocks included ''vast tracts'' of lowland public conservation land on the South Island's West Coast, ''a swathe'' of the Ruahine forest park, and lowland forest remnants in eastern Taranaki.
''The Government is pumping tens of millions of dollars into seismic surveys and the like to make New Zealand a more attractive destination for the fossil fuels industry,'' he said.
Oil Free Otago spokeswoman Rosemary Penwarden labelled the block offer a ''giant leap backwards'', given the effects on Dunedin posed by climate change.
She said Mr Bridges' block offer came two days after the International Panel on Climate Change released the second part of its fifth report.
''New Zealand can expect more frequent and severe flooding and heatwaves, more rainfall on the already wet west coast and less in the east and northeast, and sea level rise of up to 1m,'' she said.
To keep within the 2degC limit of global warming, agreed to by the world's governments, most of the oil, gas and coal already discovered had to stay unburned, she said.
Mr Hackwell said instead of ''handouts'' to those ''old industries'', the money should be used to ''create a sustainable economy which fits with our clean green image''.
''Whether it be from the risk of spills, the lasting legacy of contaminated sites, or from climate change, Simon Bridges' garage sale of the rights to our pristine oceans and treasured forest areas could leave a lasting impact on our natural heritage,'' he said in a statement.
Mr Hackwell said the ''sell-off of deep-sea rights underlines the sad fact'' that more than 99% of New Zealand's Exclusive Economic Zone (EEZ) is open for exploitation by the fossil fuels industry, while ''only a tiny fraction'' of the EEZ was fully protected from exploration activity, with full marine reserve status.
''As modelling done by the oil industry itself has shown, a deep-water oil blowout could foul vast tracts of ocean and coastline. This would significantly impact on seabirds, marine mammals, fish and other marine life,'' Mr Hackwell said.
