ONE of Hongkong's brightest and youngest politicians, Gilbert Leung Kam-ho, was jailed for three years yesterday after being convicted of trying to buy votes to secure his seat in the Legislative Council. Forty-year-old Leung was found guilty on two charges of offering an advantage to two Regional Councillors and an alternative third charge of bribing a district board member and Regional Councillor. His counsel, Cheng Huan, QC, indicated that he would appeal and asked the judge for a certificate to expedite the case. The request, and an expected application for bail, will be argued today. When announcing the sentence on the first politician to be prosecuted for election malpractices under the Prevention of Bribery Ordinance, Mr Justice Keith said: ''When corruption occurs in high places, the sentences must be severe.'' He acknowledged that Leung's political and professional careers were in ruins. ''It is a real tragedy, both for you and your family and your political colleagues, that ambition, in its political form, got the better of you,'' he said. Mr Justice Keith said the integrity of the electoral process had to be maintained if democracy was to mean anything. ''Your attempt to bribe has tarnished that integrity,'' he told Leung, a chartered surveyor and chairman of Dominion Surveyors Ltd, who in 1991 won a prestigious Ten Outstanding Young Persons award. Leung is disqualified immediately from holding public office for 10 years. The jury brought in the verdicts after almost 14 hours of deliberation. When the clerk announced to the crowd milling outside that the jury was ready, there was a rush for seats in courtroom number seven. Leung slumped forward in the dock soon after the foreman of the jury read out the verdicts, which also found him not guilty of a charge of incurring excessive expenses in the Legco elections in September 1991. Mr Justice Keith retired to his chambers while Leung received assistance. The jury was led away. Leung's wife, Susanna, rushed out of the packed public gallery to rub medicated oil around his neck and forehead. His tie was loosened and the first two buttons of his shirt were undone while more medicated oil was rubbed on him. One of the five Correctional Services Department officers surrounding Leung handed him a drink of water. He looked pale and in shock as he was consoled by his wife, watched by a packed courtroom of his supporters, family and about a dozen ICAC officers, who brought the case against Leung. After 20 minutes, Mr Justice Keith returned and Mr Cheng indicated that Leung did not want the sentencing to be adjourned. Mr Cheng asked the judge to take into account the extensive public service Leung had done for the community for a number of years. ''The convictions are a great personal tragedy to him and the greatest punishment he could suffer in the circumstances,'' counsel said. ''It is sad for Hongkong that someone who has contributed so extensively has been convicted of these three offences,'' said Mr Cheng, stressing that a deterrent sentence was not called for. ''All these years of the effort he had put into these positions have gone down the drain and that is the greatest punishment,'' Mr Cheng said. He pointed out that Leung was the first person to be charged for offering advantages to public servants under the Prevention of Bribery Ordinance. Unlike most cases featuring prominent and distinguished public personalities, there was no commotion from the public gallery when Leung was jailed. Before he left the dock, he called his wife and handed over his wallet, keys and diary. He then walked away with his head bowed. A medical report was tended to the court which stated that his poor health this week was caused by stress and anxiety due to the proceedings. On the first charge of offering $50,000 to Regional Councillor Fung Pak-tai, the jury returned a unanimous verdict of guilty. They were discharged from returning a verdict on the second charge of bribery, since it was an alternative charge for the first. Although found not guilty of offering $30,000 to Mr Fung, he was found guilty on the alternative charge of bribing Sha Tin District Board member Lau Hon-kit on account of Mr Fung having voted for him. He was also found unanimously guilty of offering $100,000 to Regional Councillor Cheung Hon-chung and again the jury was discharged from returning a verdict on the alternative bribery charge. On the seventh charge of bribing his unofficial election agent, Wai Hon-leung, with $150,000 to buy a car - the members of the jury were deadlocked. Senior Crown Prosecutor Michael McMahon indicated he did not intend to press for a verdict, so the judge ordered that the charge be left on the file. On the last charge of incurring election expenses in excess of the $50,000 limit, the jury found Leung unanimously not guilty. Leung, who was born in Macau and educated at the Chinese University, joined the civil service in 1977 as a land executive in the then New Territories District Office in Sha Tin. In 1982 he won a government scholarship to pursue a surveyor's course in England. He became a chartered surveyor in 1984. In 1985 he left the civil service and successfully stood for election for the Sai Kung District Board. In May 1991, he was elected to the Regional Council. Four months later he won the Regional Council functional constituency's election to the Legislative Council. He is also a committee member of the Antiquities Advisory Board, an executive committee member of the Heung Yee Kuk, and president of the Rotary Club in the New Territories. He was arrested outside the Hongkong Club on December 5, 1991, and had been on bail. Cheng Huan, QC, leading Philip Dykes and Peter Wan, appeared for the defence, while Mr McMahon and Dominic Lai prosecuted at the 20-day trial.