THE largest group of Vietnamese to return home voluntarily landed in Hanoi yesterday aboard a specially chartered Boeing 747. The 369 migrants were part of the voluntary repatriation programme of the United Nations High Commissioner for Refugees (UNHCR) - a programme that has been a subject of major concern for the Government. Officials are trying to agree with Hanoi on a date for talks on the programme, which has been stymied by refusals from Vietnamese officials to accept non-nationals of Vietnam. Refugees Co-ordinator Brian Bresnihan is hoping to discuss the issue as a matter of urgency, but diplomatic relations between Hong Kong and Hanoi have been frosty in recent weeks. Governor Chris Patten has threatened to cancel a visit to Hanoi scheduled for early next year unless Vietnam agrees to talks. Hong Kong has been forced to release more than 120 people who have applied for repatriation, but been rejected by Hanoi. Their continued detention would have been illegal. The surge in voluntary repatriation numbers this month and the record 369 who departed yesterday has been attributed to people rushing to take advantage of an additional US$150 (HK$1,160) repatriation grant which is only on offer until the end of this month. Yesterday's flight, the last for the year, comprised 128 men, 103 women and 138 children. They were the 223rd batch to go back under the programme. The returnees included three unaccompanied minors who were sent back under the UNHCR's Family Reunification Programme. The group brought to 5,581 the total number of Vietnamese migrants who had returned voluntarily this year, and to 44,194 the total number of returnees since the programme started in March 1989. The 5,581 people returned home under UNHCR auspices on 38 charter and commercial flights at a cost of $12.7 million to the UNHCR. Normally, only about 150 people are returned per charter flight. A total of 22,586 Vietnamese remain in Hong Kong detention centres. The Hong Kong Federation of Trade Unions accused the Government of using double standards in its treatment of illegal immigrants from China and Vietnamese boat people. The unionists called on the Government to explain why 141 Vietnamese boat people recently released from detention were allowed to seek work in Hong Kong while other illegal immigrants were jailed if found being employed in the territory.