The government must set a cap on Hong Kong's population in a reversal of its previous approach to town planning, a leading environmental organisation says. Speaking ahead of Chief Executive Leung Chun-ying's policy address on Wednesday, the Conservancy Association's senior campaign manager, Peter Li Siu-man, said the government risked repeating the planning mistakes of the past unless it considered how many people the city could realistically accommodate. The idea of setting a limit on population has been widely debated, despite the fact the government explicitly ruled the idea out when it launched a consultation on population policy last month. "Instead of setting a cap then doing the town planning, which is the correct approach, we are doing the exact opposite," Li said, adding that the thinking seemed to be that there was "unlimited land supply." "But does that mean we have to use all this land to build homes … with no public facilities?" he asked. Li said the idea of a population cap was first touted in 1948, when British town planner Professor Patrick Abercrombie set out the first master plan for the then-colony. He put the figure at two million, based on the scarcity of land. The population now stands at more than 7 million. "The town planning concept of this town will regress by some 66 years if we stick with the current approach," Li said. Li warned that the excessive density of planned new-town developments in areas such as Tuen Mun, Yuen Long and Kam Tin risked a repeat of the mistakes of Tin Shui Wai, the new town built in the 1990s now associated with poverty and social ills. He said planning for new towns ignored the fact the East and West rail lines were already congested, and focused too much on the provision of roads. Li also called on the government to take real action on conservation and accused Leung of failing to live up to his campaign promises to environmental groups, including protecting country and marine parks, promoting green tourism and revitalising farmland. Leung's conservation credentials have been called into question, not least after development minister Paul Chan Mo-po raised the possibility of building in country parks as the city scrambles to find land to ease a housing shortage. "C.Y. Leung's rise to prominence actually relied on good relations with environmental groups and many of his environmental promises during his election campaign came from these groups," Li said. "Now he's making a 180-degree turn and the mask is coming off." He said the government was blatantly ignoring the findings of previous studies, such as the 1998 Territorial Development Strategy Review and the 2007 Hong Kong 2030 Planning Vision and Strategy, in bringing forward plans for new towns and not introducing more marine parks.