Hong Kong’s housing minister has failed to explain to lawmakers how the city’s leader decided 800,000 was the magic number at which the supply of public sector rental flats would be enough to satisfy demand from low-income families. Some legislators on Monday said they suspected the number was just “made up”, while others said Secretary for Transport and Housing Frank Chan Fan had no clue where it came from. Chan’s grilling at the city’s legislature came after Chief Executive Carrie Lam Cheng Yuet-ngor on Friday said that when the stock of public rental housing reached “a certain number, such as 800,000, it may be enough to meet the demand of the poorest families over a period”. But in a meeting of the panel on housing at the Legislative Council on Monday, lawmakers from both sides of the city’s political divide questioned how Lam had reached that number. “There has been no explanation of where it came from,” said pro-establishment legislator Regina Ip Lau Suk-yee, of the New People’s Party. Ip said Lam’s comment might encourage more people to buy a flat, which would be risky when interest rates were rising. Facing repeated questions from members of the chamber however, Chan said he had nothing to add to Lam’s comment. Housing chief tries to defuse fears about cutbacks on building of rental flats for low-income residents “The chief executive has explained her words very clearly,” he said. “I am not evading the question. I indeed have nothing else to add.” Chan said the Housing Authority, Hong Kong’s biggest provider of public housing, had been reviewing a pilot project to decide whether to continue a scheme that encourages public housing renters to buy subsidised housing so they will move out and free up rental units for those in need. The review was expected to be completed early next year. Fernando Cheung Chiu-hung, of the Labour Party, said Lam had ignored the authority’s review by putting the 800,000 figure out there. He suspected Lam had simply “made up” the number. Eddie Chu Hoi-dick, of the Land Justice League, said he suspected Chan did not know what Lam meant. Housing stress is harming Hongkongers’ mental health On Friday Lam said that after the supply of rental flats reached 800,000 the government would prioritise building subsidised flats for sale instead. These flats would be sold to public housing renters or those waiting for rental flats under the Green Form Subsidised Home Ownership Scheme. The initiative aims to encourage renters to vacate their flats for Hongkongers on the waiting list by diverting them to buy subsidised flats. As of March, there were 769,000 public rental flats under the Housing Authority. As of June, some 280,000 households were on the waiting list for a rental unit. Stanley Wong Yuen-fai, chairman of the authority’s committee on subsidised housing, said Lam’s number was not scientific because it was so difficult to estimate how many families would need housing. He said he was worried the green form housing scheme might not attract enough renters to buy.