The former financial secretary has suggested Hong Kong strike a deal with Zhuhai to set up an incinerator on an uninhabited islet where the city's rubbish could be disposed of.
Antony Leung Kam-chung raised the idea at a seminar yesterday on how the city should cope with its challenges.
Leung said a shortage of land was hindering the city's development - citing the ongoing dispute over government plans to build new towns in the northeastern New Territories, and conflict over rezoning green belts for housing.
He said the answer was for Hong Kong to form an alliance with neighbouring cities in the Pearl River Delta - including deals that enabled Hong Kong to make use of mainland land.
"Zhuhai is close to Hong Kong and will be just an hour's drive away once the Hong Kong- Zhuhai-Macau bridge is open.
"Zhuhai has lots of land … We could ask it to allow Hong Kong to build incinerators or landfills on some remote islets in its waters. That could save us from disputes over the construction of these facilities," Leung told the seminar hosted by the Beijing-based Chinese Association of Hong Kong and Macau Studies, the Bauhinia Foundation Research Centre, and the One Country Two Systems Research Institute. It was mainly attended by researchers from local think tanks.
The government is facing strong opposition to its proposal to expand the Tuen Mun, Tseung Kwan O and Ta Kwu Ling tips until a planned incinerator off Shek Kwu Chau - also a contentious project - is ready.
Leung, who is tipped as a potential candidate for the 2017 chief executive election, also said many Hongkongers were dissatisfied with the government because they felt the city was losing out to its competitors.
On competitiveness, political disputes were seen by some speakers as weakening the city's competitive edge. It was suggested that the city try to lure more professionals from the mainland to work in Hong Kong.