Taxpayers could have to foot an extra annual $4 billion bill for medical, education, and welfare services if mainlanders with the right of abode were to move here within two years. And an extra 20 hectares of land will be needed to build homes for them, according to research by the Democratic Alliance for the Betterment of Hong Kong (DAB). While the alliance is trying to avoid stepping into the legal controversies over the power of the National People's Congress and its Standing Committee, it says it supports the court ruling. The DAB says the influx of mainlanders will mean Tung Chee-hwa's pledges on public housing and quality education will fall flat. Assuming 500 eligible mainlanders are allowed entry each day, taxpayers will have to find an extra $1.75 billion a year for education, with an immediate need for 45 secondary and primary schools. The DAB's education spokesman, Yeung Yiu-chung, in releasing the research yesterday, warned the plan to have 60 per cent of primary pupils in whole-day schooling would have to be pushed back. Colleague Gary Cheng Kai-nam warned: 'Mr Tung's pledge to shorten waiting time for public housing will fail. And overcrowding problems in public housing will worsen.' Mr Cheng said that if 500 new arrivals came each day, all the estimated 320,000 eligible mainlanders could settle here in two years, which the alliance thought was a reasonable time frame. On medical services, the research estimates an extra annual $1.7 billion in recurrent spending will be needed. The DAB's medical spokesman, Dr Lo Chi-keung, said: 'In the next 10 years, we shall need two or three more hospitals, which means another $10 billion or so, to maintain our medical services at our present standards.' The Society for Community Organisation's director, Ho Hei- wah, who led the court battle to win right of abode, accused the alliance of exaggerating the impact of the influx. 'It is not fair to paint a gloomy picture when they do not get the accurate figures. We need not have to take all mainlanders in two years. Many of them will accept a four-year wait,' said Mr Ho. A spokesman for Chief Secretary Anson Chan Fang On-sang, who chairs a taskforce on the possible influx, was not available for comment yesterday.