TUNG Chee-hwa's pledge to cut needy families' wait for public housing to three years could fall flat, housing officials admit. A rethink of housing policies is under way after the Court of Final Appeal's right of abode ruling last month. Acting Business Director Fung Ho-tong said yesterday the ruling could lengthen the waiting list and the department was assessing the impact. According to a 1996 survey, about 17 per cent of new arrivals needed public housing. But recent estimates have put the figure at 30 per cent. Housing Authority chairwoman Rosanna Wong Yick-ming has ordered a rethink of the present policies. She is determined to keep the Government's promise of cutting the waiting time for public housing to three years by 2005. But officials said they were not sure the target could be achieved. An earlier proposal to make it easier for migrant families to get public units is understood to have been shelved. Under present rules, the majority of an applicant's family must have lived in the SAR for seven years to be eligible. In the case of a couple, both must have at least seven years' residency. About 20,000 applications by new migrant families have been held up because of the seven-year rule.