MOVES to encourage rich tenants to vacate public housing in favour of some of the 150,000 needy households on the Government waiting list are peppered with loopholes, say concern groups. The Housing Authority is considering requiring the 640,000 families living on its 200 public estates to prove they are in real need of subsidised accommodation or face paying market rents. Under the proposals, due to be finalised next month, a tenant who has lived in public housing for 10 years must declare ownership of stocks, local and overseas properties and cars. Tenants with assets over a certain value will be charged market rents for their flats, while those who do not declare their assets will automatically be treated as 'wealthy tenants'. The authority has not yet decided on the 'wealthy line' but one option is 150 times the income limit for public housing. Given that the average rent for an urban flat is about $2,000, a family of four would be liable to pay up to $10,000 a month if found to have assets worth more than $2 million. The authority expects about 12,000 tenants to be required to pay market rents under the new measures. Officials have dropped earlier proposals to evict better-off tenants, considering it too harsh. An ad hoc group, chaired by Housing Authority member Professor Yeung Yue-man, is finalising the proposals. But some members and concern groups have pointed out an 'obvious and fatal' loophole which may force the scheme to fall through. A family could transfer assets to a member who withdraws from the tenancy registry. They could even become a 'worse-off' household and be eligible for rent remission. A household could escape the clampdown by selling assets to limited companies they set up. Member Hau Shiu-pui, who vowed to vote against the scheme, said: 'The scheme appears to be more academic than practical. For example, stock prices can drop greatly in a night. That you own lots of shares does not mean you are always rich.' Mr Hau also criticised the scheme for discouraging people from creating wealth. Association for Democracy and People's Livelihood vice-chairman Leung Kwong-cheong said the authority should use a 'positive approach' to get tenants to buy Home Ownership Scheme flats. An earlier survey by the authority found over 13 per cent of tenants owned other flats - up to five in some cases. Governor Chris Patten has ordered the authority to take more forceful measures to solve the problem of rental flats being occupied by wealthy tenants. Long-term public tenants are subject to income checks every 10 years. Under the so-called double-rent policy, families whose incomes exceed three times the income limit will be charged twice the normal rents. Some families have wait up to 10 years before getting a public housing flat.