Front runner Leung Chun-ying yesterday frantically lobbied his supporters ahead of Sunday's Election Committee vote for the city's next chief executive, possibly coming within at least a dozen ballots of avoiding an abortive result. Leung, now widely seen as Beijing's preferred choice, is apparently still short of the 601 minimum votes needed for an outright win, after securing only 510 to 590 votes by late yesterday - many at the expense of chief rival Henry Tang Ying-yen - according to the latest count by the South China Morning Post. Whoever wins will need to secure more than half of the maximum of 1,200 votes, with a second round of balloting scheduled for Sunday afternoon if the first fails to produce a clear winner. But only 1,193 votes are available, due to vacancies. Should that fail, a run-off will be held on May 6 after a fresh round of nominations. The number of votes pledged to Leung could rise by Sunday if members in subsectors like engineering and accounting, many of whom have yet to make their intentions public, back Leung, the former Executive Council convenor, who last month had 305 votes pledged. Yesterday, Leung saw the number of his declared supporters climb steadily as the Federation of Trade Unions decided that all 60 members would back him. About a third of them have nominated Leung, while none have nominated Tang. With the uncertainties, it remains unclear whether Leung can beat his rivals Tang and pro-democrat Albert Ho Chun-yan, with some electors considering blank ballots. Tang's supporters like tycoon Li Ka-shing still back him, while Sino Group chairman Robert Ng Chee Siong has yet to say if he will withdraw his support. Ng Hong-mun, a former local deputy to the National People's Congress, said he believed an abortive vote may arise should many of Tang's former supporters insist on not voting for Leung, and cast a blank vote. Cheng Yiu-tong, the federation's president, said more than 10 members who favoured Tang had changed their minds after the scandals over his extramarital affair, illegal basement in his home and his apparent belief that public interest could override confidentiality rules. 'The incidents have left Election Committee members very disappointed.' Political group New Forum convenor Ma Fung-kwok, a Leung nominator, said it suggested their 23 members and allies vote for Leung. Eight of them had earlier nominated Leung. The pro-Beijing Democratic Alliance for the Betterment and Progress of Hong Kong, with 147 votes, will discuss its intentions today, while the New People's Party, with six seats, will decide tomorrow. Hopewell Holdings chairman Gordon Wu Ying-sheung, who nominated Tang, chatted with Leung at his campaign office yesterday. Asked if he may change his mind, he told Cable TV: 'I have never made up my mind [on who to vote for].' 601 The minimum number of votes needed on Sunday to win the election to become Hong Kong's next chief executive.