The Hong Kong government might negotiate with the People's Liberation Army in a bid to release vacant military sites for infrastructure and education projects should the need arise, the security chief said yesterday. But Ambrose Lee Siu-kwong said the government had no right to interfere in defence matters and it might have to provide new sites in exchange for any facilities released by the army. During Legislative Council question time yesterday, lawmakers expressed concern that many PLA sites - several of which occupy prime areas - appeared to be underused. 'Many people see it clearly but the government dares not raise the issue, which is irresponsible,' lawmaker Cyd Ho Sau-lan said. 'Many of the barracks are rarely used and could be returned to the community.' Ms Ho said an army barracks site in Kowloon Tong could be used to build student accommodation for Baptist University and City University, while barracks in Shek Kong could be used to resettle villagers affected by a cross-border infrastructure work in Yuen Long. Democratic Party lawmaker Lee Wing-tat suggested that the government investigate whether prime PLA city sites could be developed. Under a pre-1997 Sino-British agreement, 14 of 39 former British Army sites were handed to the PLA. The rest were redeveloped. Beijing promised that if any site used by the garrison 'is no longer needed for defence purposes, it shall be handed over, without compensation, to the government'. National laws also allow the Hong Kong government to take over military sites if it can provide an alternative. Ambrose Lee said that while the government had no record of how many soldiers and family members were in Hong Kong, his understanding was that all of the army sites were used for defence purposes. But the security chief conceded that it was possible for the government to kick-start the site-swapping mechanism. 'If there is a need for infrastructural and education development purposes, we can start the second mechanism,' he said. A spokesman for the PLA said all 18 barracks at the 14 sites were being used for defence purposes.