The New South Wales Government has refused permission for a $600 million coal mine in a key central coast electorate.
Mining firm Kores, which is owned by the South Korean Government, had planned to extract 5 million tonnes of coal a year from the Wallarah 2 mine, near Wyong.
The long wall mine was also expected to employ 300 people.
Planning Minister Tony Kelly says water and subsidence issues led to his refusal.
"The Planning Assessment Commission had suggested it could go ahead with a significant number of conditions that could be worked out later on, and I believe there were too many uncertainties," Mr Kelly said.
Alan Hayes from the Australian Coal Alliance says locals were united in their resistance, from the Wyong Council to businesses and residents.
"I think there will be champagne corks popping today," Mr Hayes said.
Wyong's sitting Labor MP David Harris had objected to the mine, while the State Opposition had promised to block it.
Labor holds the seat by a margin of 6.9 per cent over the Liberal Party.
Mr Kelly's decision to refuse permission comes just two days after he moved in favour of the Barangaroo development in central Sydney.
The minister issued an order of Wednesday that weakens a legal challenge to the project in the state's Land and Environment Court.
