The company behind the New Acland coal mine on the Darling Downs west of Brisbane has been trying to expand its open-cut coal mine for nearly 14 years.

But farmers and community members with the Oakey Coal Action Alliance (OCAA) have objected, raising issues about air quality, dust, noise, climate change and impacts on soil and water.

The High Court on Wednesday ordered the matter be returned to the Land Court for a new hearing.

The outcome of that hearing has to be taken into account by the Queensland government in deciding to grant or reject the mining application.

The Land Court must consider whether mining operations conform with sound land use management, whether there will be any adverse environmental impact and whether the project is an appropriate use of the land taking into account current and prospective land uses, the High Court judges said.

The latest decision follows a five-year legal battle that included a 100-day hearing in the Land Court – the longest in its history – and actions in both Queensland’s Supreme and Appeal courts.

The Court of Appeal decision in 2019 found earlier recommendations were affected by “apprehended bias” but did not order the Land Court to hold another hearing.

New Acland argued its applications had been outstanding for a long time and should not be referred back to the Land Court for “yet another potentially lengthy and costly hearing”, the High Court judgment says.

The company also said it had spent more than $25 million to ensure the expansion could proceed immediately once approved and OCAA “had its day in court”.

But Justice James Edelman said such matters were “insufficient to justify the highly exceptional course of this Court refusing a rehearing for a party whose hearing was decided other than independently and impartially”.

“Indeed, it cannot be said that Oakey Coal Action has ‘had its day in court’ or had lost all of its grounds before an independent and impartial tribunal,” he added.

New Acland has also been ordered to pay OCAA’s legal costs of the High Court appeal.

OCAA secretary Paul King said the result was “a better outcome than we could have hoped for”.

“The High Court’s decision is, in our view, vindication that the Darling Downs is for farming – not coal mining,” he said in a statement.

The Environmental Defender’s Office, which represented OCAA, said the decision would give objectors the opportunity to present their evidence of the impacts of the coal mine on the local farming area.

“It is fundamental to the administration of justice that our client and the other objectors have access to an independent decision unclouded by apprehensions of bias or unfairness,” EDO managing lawyer Sean Ryan said.

-AAP