A leading conservation body has suffered a serious setback to its legal challenge of the Scottish Government's decision to approve a large-scale wind farm without a public inquiry.

The 67-turbine Stronelairg wind farm in the Monadhliath Mountains to the east of Loch Ness is being developed by energy giant SSE.

It was opposed by the Government's advisory body on nature and landscape, Scottish Natural Heritage, and by the Cairngorms National Park Authority.

The John Muir Trust (JMT) lodged a petition in the Court of Session asking for a judicial review of the decision in June by Energy Minister Fergus Ewing.

Now the wild land charity is considering the implications of Lord Phillip refusing to grant it a Protective Expenses Order (PEO).

The JMT says the PEO procedure exists to make it possible for anyone to take a case to the courts to protect the environment in the public interest; and to be able to do so without the risk of prohibitive legal costs from the other parties.

Stuart Brooks, chief ­executive of the JMT, said: "Today's decision suggests that charities in Scotland will find it extremely difficult to obtain a measure of protection from very high legal costs when bringing environmental cases in the public interest."

He said the charity would examine Lord Phillip's ruling and in the meantime seek donations to allow it to carry on with the legal case.

SSE earlier said it was particularly disappointed by JMT mounting a legal challenge. It says the development would provide up to £30 million of community funds over 25 years.