Greenpeace argued that the cost of a linked island cluster, amounting to HK$580 billion with more than 1,000 hectares of reclaimed land, requires extensive public consultation.

The 10 others were Green Power, Clean Air Network, Peng Chau Reclamation Concern Group, Save Lantau Alliance, Green Sense, Hong Kong Dolphin Conservation Society, The Green Earth, Greeners Action, Hong Kong Bird Watching Society and Designing Hong Kong.

The artificial island cluster, slated for completion in 2033, aims to provide up to 210,000 flats and around four million square meters of office space.

But authorities only released a Legislative Council paper in December without issuing any press releases or providing a channel for people to submit views. A public consultation website only came into being on January 19.

"That cut the three-month public consultation down by a quarter, which in effect suppressed the right of public participation," a Greenpeace spokesman said.

The group reviewed major development projects in the past 10 years and said this was the first time a big infrastructure project has not been subject to public consultation, "setting the worst precedent ever."

It also cited a funding application to the Legislative Council in 2020, with more than HK$10 million set aside to conduct two rounds of public consultation.

So the administration was urged to withdraw from the project and to justify the need for such a project.

There was also a call on the administration to prioritize developing 2,000 hectares of brownfield sites to alleviate the housing crunch.

That includes 433 hectares of brownfield sites that Greenpeace and think tank Liber Research Community identified in October, located within the area designated for the massive Northern Metropolis scheme but excluded from plans.