CAMPAIGNING for today's by-election has been subdued. There are no street banners, no canvassers knocking on doors. The reason? Only 35 voters are eligible to cast their ballot for candidates vying to replace Gilbert Leung Kam-ho, now serving a three-yearjail term for corruption. Leung was found guilty of offering a $50,000 bribe to fellow Regional Councillor Fung Pak-tai and giving $100,000 to another councillor Cheung Hon-chung in return for helping him get elected to Legco. Not surprisingly, there is little talk of vote-buying in this election. While recommendations have been submitted to the Government to improve electoral arrangements, they will not be in place for today's election. ''In the past, people openly gossiped about vote-buying during the election period. But not this time. People don't dare touch this topic because it might lead to people being arrested,'' said one Regional Councillor, referring to the arrest of Leung only three months after being elected to Legco by his Regco colleagues. The Independent Commission Against Corruption (ICAC) and the Constitutional Affairs Branch are closely watching the by-election to ensure there is no repeat of the Leung incident. The ICAC, which earlier admitted that ''tea money'' was commonplace in New Territories constituencies, has vowed to stamp out corruption in elections to ensure they are clean. Leung corruptly secured his Legco seat in September, 1991. Three witnesses appeared in the trial to give evidence. Fellow Regco member, Fung Pak-tai, was found with an alleged $30,000 bribe from Leung in his home. He has resisted calls to step down and says not only does he plan to vote today, it is his civic responsibility. But, he added, ''if the weather is too hot, I may not go [to cast his vote]''. Councillors contacted were cautious in commenting on relationships between candidates and their Regco colleagues. There are four candidates with Alfred Tso Shiu-wai tipped to win over independent Yeung Fuk-kwong, former United Democrat Lau Kwong-wah and United Democrat Chow Yick-hay. All are running for office for the second time. Like Leung, indigenous resident Mr Tso is a compromise candidate who has the backing of the dominant rural faction in Regco. Due to the circumstances under which Leung was unseated, Mr Tso, a member of the Liberal Democratic Federation, has been especially cautious in his lobbying. ''When I speak to Regco colleagues face to face, I do it in a group so that there is no chance whatsoever of me being alone with another elector. ''There have also been times when I have lobbied colleagues over the phone. But our conversation could never be secret because I expect our phones are being bugged,'' he said. In a meeting of rural leaders earlier this month, Mr Tso successfully challenged Lam Wai-keung and Poon Chin-hung and gained the endorsement of the rural faction, led by political heavyweight Regco chairman Cheung Yan-lung and Heung Yee Kuk chairman Lau Wong-fat. The show of unity is a sign that the rural faction is keen to keep the seat under its control rather than have it fall into the hands of outsiders, meaning ''democrats''. The Regco seat has been occupied by candidates who have been approved by its rural leaders since it was first introduced in 1986. However, the rural force is not as unified as it seems. Mr Lau and Mr Cheung head different factions. Although Mr Tso has the endorsement of both rural leaders, loyalties could be divided among members when they cast their votes. As Mr Tso said: ''The by-election will be a real test of unity [of the closely-knit rural community].'' But his closest rival, Lau Kwong-wah, does not see the by-election as a struggle between the rural and non-rural faction. Lau Kwong-wah stands a better chance of winning if he manages to reach the second round of voting. Then the independent and liberal members' votes might swing to him. Candidate Chow Yick-hay said he was taking part in the election for the exposure rather than with the aim of winning because liberals are in the minority in Regco. ''In a functional constituency with an electorate as small as 35, any poll result will be decided by one's personal relationships with others, rather than one's ability and track record,'' said Mr Chow. ''I can't see any chance of a major breakthrough as long as there is a Regional Council functional constituency seat,'' he said. The Council is dominated by rural figures with nine members from rural-controlled district boards in the New Territories. Another three are ex-officio members from the Heung Yee Kuk. It is also said that the Government's appointees to Regco are made according to the recommendations of rural leaders. However, Mr Chow did reach the last round of voting in the 1991 Regco functional constituency election to Legco. He lost the seat to Leung by five votes. Mr Yeung, who believes he can only get a few votes from independent Regco members, is expected to be the first to be knocked out, if more than one round of voting is required. ''It is highly likely that Mr Tso will win the first round because [rural members] are united on this particular issue,'' he said.