A MAJOR battle over funding may lead to the United Nations pulling out of Hongkong's Vietnamese refugee camps by the end of the year, leaving the territory's taxpayers facing an additional $25 million bill to keep detention centres running with services intact. The move, almost certain to spark a furious row among Hongkong's politicians already angered by the $1 billion burden of the boat people, has been predicted by the UN High Commissioner for Refugees, Mr Robert Van Leeuwen. Citing unprecedented global demands on resources due to natural disasters and unrest, Mr Van Leeuwen told the Sunday Morning Post the Comprehensive Plan of Action (CPA), which oversees the repatriation of boat people, was under ''reassessment''. It could be terminated at the end of the year, he said, when all the Vietnamese should have been screened but not necessarily returned. The moves to end the plan come from donor nations who claim the money will be better spent elsewhere. ''There are simple and stark realities to be faced,'' Mr Van Leeuwen said. ''Demands on our staff are unprecedented this year. Many of our staff are putting their lives at risk in situations around the world. ''We have to put this in a global situation.'' He said it was generally recognised it was time to review how the organisation was dealing with a large, screened-out population which did not want to return to Vietnam. ''It is an absurd situation for the UNHCR to be involved with,'' Mr Van Leeuwen said. ''There is a point, as a humanitarian organisation, where there are limits as to what we can do.'' Last week, Mr Van Leeuwen revealed the detention camps were being subjected to an unprecedented crime wave, with girls as young as four being raped. Last Monday, when he addressed a crowd in sections 1 and 2 at Whitehead Detention Centre, two men slashedtheir stomachs in front of him. ''It is not the normal function for the UNHCR as a humanitarian organisation to be responsible for control of crime,'' he said. ''This must be the responsibility of the Hongkong Government.'' Mr Van Leeuwen said there had never been such an effort to persuade non-refugees to return to their country of origin. He said returnees were provided with credit schemes, vocational training and other incentives, and were monitored after their return by welfare agencies. ''In that situation how will the international community continue to fund a very costly programme of non-refugees in this region who are simply choosing not to return? ''I believe this is the last year, 1993, in which we can count on full donor support.'' Mr Van Leeuwen said those suggesting an end to the CPA were some of the countries in the region, and a number of the heads of UNHCR offices in Southeast Asia. The UNHCR has an annual budget of about US$100 million (HK$780 million) to administer the Comprehensive Plan of Action, provided by donor countries, mainly the United States, the European Community (EC), Japan and Britain. It is becoming harder to raise the funds every year. The UNHCR still owes the Hongkong Government US$95 million. The biggest threat to the CPA comes from funds drying up as traditional donors shift their finances to other parts of the world, like Bosnia and East Africa, where human suffering on a massive scale has developed. Last year the UNHCR had to cut back on certain activities, including legal assistance to monitor screening, as the body came under increasing criticism for the services provided in Hongkong. If the UNHCR pulls out of the camps, it is feared the Government will pare services to the bone in order to placate public opinion, which already believes too much taxpayers' money is being spent on the boat people. A Government official said: ''If the services are withdrawn because people haven't got the money to pay for them, they are withdrawn. ''It is by no means certain that if funding is stopped the Government would pay for it. It would be looked at on its merits.'' Mr Van Leeuwen said ending the CPA would have to be thoroughly examined before any decision, but there was no question of resettling non-refugees in third countries. Under the CPA - drawn up by 70 nations at a UN conference in 1989 - the UNHCR oversees the repatriation of Vietnamese through all stages of the process, including screening and status review boards; it also co-ordinates all non-government agencies and monitors refugees after their return. Ms Lorna Workman, external information co-ordinator for the EC international programme, said the EC also had demands to divert funds away from the Vietnamese problem ''for other crises which are more critical''. Ms Workman said the EC would like a sliding scale on the money paid to returnees. This would cut the amount of money each person received the longer they refused to return. At the moment, those returning are paid US$50 each at the airport and then US$360 per person over a year for re-establishment. Government Refugee Co-ordinator Mr Brian Bresnihan said there had been a significant drop in the number of voluntary repatriations, although he claimed it was always lower at the start of the year. The numbers of Vietnamese opting to return home has dropped to 2,783 so far this year, compared with 12,000 last year. A total of 29,000 have gone back since 1989. Of the 39,484 Vietnamese in camps in Hongkong, 30,400 have been screened out, 2,394 have received refugee status, while the remainder are waiting to be processed. Mr Bresnihan said it was ''completely hypothetical'' to discuss the issue at the moment as no decisions had yet been made on the future of the programme. Mr Bresnihan said ''first instance screening'' was due to finish by the end of the year but the appeal process would last until June 1994. Oxfam director Mr John Torgrimson said the potential for the UNHCR to pull out of the CPA could fall in line with the end of screening. As part of his personal effort to speed up repatriations Mr Van Leeuwen last Monday warned a crowd of up to 4,000 screened-out Vietnamese in Whitehead ''in no uncertain terms'' that funding could end next year.