Chung Yiu-wa, president of the union, said: "Many of our student hostels and classrooms boast the sea view of Tolo Harbour. We've always been close to the sea and this has been part of our campus memory.

"But sea view is not the most important thing. We don't think reclamation is justified. The government hasn't made good use of existing land, like disused barracks," he added. The current consultation had also failed to take into account the reduction in the city's projected population in 30 years, which was revised down to 8.47 million from 8.89 million last year, he said.

It has been proposed that 30 to 60 hectares be reclaimed from Ma Liu Shui for housing, and the area could benefit from the upcoming Sha Tin to Central MTR link. Another initiative in Sha Tin is to move a sewage treatment plant, which occupies 28 hectares, into a cave in order to release land for more homes.

Other sites identified for the consultation on reclamation include the coastal areas of Tsing Yi, Tuen Mun, Sunny Bay and Siu Ho Wan on Lantau. An artificial island is also proposed for the waters off eastern Hong Kong.

They would altogether generate more than 2,000 hectares of new land.

Green groups have objected to the selection of Lantau and the idea of a man-made island, saying this would be harmful to the Chinese white dolphin.

The exercise also asks the public to express views on rock cavern developments at Sai Kung, Diamond Hill and Sham Tseng, which would involve relocating sewage works into nearby caves to release the land for development.