THE repatriation of 2,447 ethnic Chinese Vietnamese illegal immigrants will start next week under a deal hammered out yesterday by Hong Kong and mainland officials. About 100 will be driven to the border on September 3, but it could be months before all the Chinese-born Vietnamese have left the territory. Hong Kong agreed to Chinese calls during yesterday's meeting in Guangzhou that the territory should pay for those illegal immigrants from Guangxi and Hainan provinces to be sent home by boat. But for those sent back over land, Hong Kong will be responsible only as far as the border. The cost to Hong Kong and the timetable for completing the repatriation could not yet be estimated, as detailed arrangements still had to be made, said the leader of the Hong Kong delegation, acting political adviser John Ashton. Those details would be the subject of further discussions today with the Chinese side, led by Xu Liugen, director of the Office for Indo-Chinese Refugee Affairs in the Ministry of Civil Affairs, based in Beijing. One sticking point could be the identification of the immigrants, said by the Chinese to have come from 200 farms spread across Guangxi, Guangdong, Hainan, Fujian, Yunnan and Jiangxi provinces. Mr Xu said false identities had been given by some of the illegal immigrants, most of whom are being held in Chi Ma Wan detention centre and who claim to have fled Beihai, Guangxi, where they say their homes were bulldozed to make way for development. But Mr Ashton said he was convinced the Hong Kong Immigration Department was obtaining and forwarding accurate information. A liaison office is to be established in Guangdong to ease the repatriation and Chinese officials may travel to Hong Kong to check identities. An agreed statement said: ''The first group will return to China next week on September 3. Thereafter returns will continue in batches in an orderly manner until all those who have previously settled in China have returned.'' Legislator Howard Young described the deal as ''excellent news'', while his colleague Jimmy McGregor praised China for being helpful to Hong Kong and for recognising the problems the territory had. Both legislators said they would be prepared for Hong Kong to shoulder part of the costs to ensure speedy repatriation. ''I think the deal on costs is quite reasonable, even though it will involve a number of millions of dollars,'' Mr McGregor said. ''The alternative is that they stay here and the Hong Kong Government bears the costs of looking after them, and that is also very high.'' Mr Young agreed, saying he did not want to ''haggle over the dollars and cents'' and then see the deal collapse. He said the real significance of the agreement was that it sent a very clear message to any Vietnamese in China thinking of coming to Hong Kong that they would be sent back. The agreement comes a month and a day after China said it would ''accept the repatriation'' of the 1,100 ex-China Vietnamese illegal immigrants then in Hong Kong's detention centres. In the interim period, more continued to arrive and Hong Kong had been unable to get a response to requests to sort out details, despite the issue being raised in London, Beijing, and daily in Hong Kong with officials of Xinhua (the New China News Agency). The influx of illegal immigrants has put severe strain on Hong Kong's resources in terms of providing accommodation and staffing. Clearance from the Finance Committee may be needed before Hong Kong can charter a ship to return the immigrants from Guangxi and Hainan. The ferry used in a similar repatriation to Beihai in 1987 has been sold and it is believed there are no suitable ferries in the territory. Hong Kong will provide food and security for the trip. Mr Ashton, whose team included Deputy Secretary for Security Ken Woodhouse and Deputy Immigration Director John Yeung Hin-chung, said he did not foresee a problem with those repatriated heading for Hong Kong again. Mr Xu, accompanied by Lee Changyou of the Public Security Bureau in Beijing and officials from Guangdong, Guangxi, and Hainan, agreed but said there would be problems in resettling the people. ''Many came from community farms and have had their homes reallocated to other families.'' So far, China has verified 800 names from more than 2,000 provided from Hong Kong. Some people may be identified as not being former Vietnamese refugees, but they would be returned to China under normal procedures for repatriating illegal immigrants. Any ex-China Vietnamese illegal immigrants arriving in the future would be sent back quickly under the arrangement.