Fifteen organisations filed an appeal against a development on a sensitive site in Dwejra, on Wednesday.
The non-governmental organisations have crowdfunded more than €3,000 for the cause after the Environment and Planning Review Tribunal overturned the original decision by the Planning Authority.
The development would allow a restaurant to install further lighting in the area, with the Astronomical Society of Malta warning that the area would be affected by too much light pollution.
In a joint statement the organisations said that in the area one can observe the Milky Way while the Shearwater nests in the cliffs.
The arguments for and against the development will now be presented in the hearing which is set for 16 October.
The NGOs are BirdLife Malta, Bicycle Advocacy Group, Din l-Art Ħelwa, FAA – Flimkien Għal Ambjent Aħjar, Friends of the Earth Malta, Isles of the Left, Light Pollution Awareness Group, Moviment Graffitti, Nature Trust – FEE Malta, Ramblers Malta, Archaeological Society Malta, the Astronomical Society of Malta, Institute of Space Sciences and Astronomy – University of Malta, Wirt Għawdex and Żminijietna – Voice of the Left.