Former High Court Judge Peter Salmon (QC), chairman of the four-member panel of commissioners which heard the application during July and August, yesterday said the plant's 320MW operating conditions would be among the most stringent ever imposed on a coal-fired station in Australia or New Zealand.

The commissioners imposed almost 160 conditions - including dozens covering discharges to air, water and land – to the MRP’s 35-year operating consent for the station at Ruakaka, east of Whangarei.

MRP spokesman Neil Williams said the company would not make a final decision on whether to proceed with the power station until the consent process was complete.

Salmon said the commissioners – himself, Australian air quality expert Mark Goldstone, Auckland water and landfill expert Garry Venus, and Auckland planner David Hill - were particularly aware of the high value the public placed on the wider Bream Bay environment and the air quality issues raised in submissions.

But Greenpeace described the commissioners’ decision as “one giant leap backwards, back to outdated, polluting energy sources” and said that “the best of a dirty bunch is still dirty”.

ECNZ (Electricity Corporation of New Zealand) built Marsden B in the 1980s to run on fuel oil and MRP inherited the plant on the break-up of the former government monopoly in the late 1990s.

But the station has never run. MRP wants to repower it on coal as oil is far too expensive, natural gas is not available in sufficient quantity in Northland, nor is a pipeline upgrade to supply sufficient gas to Marsden B a feasible option.