Legislator David Chu Yu-lin announced yesterday that he would not run in the Legco elections for 'personal reasons'. The decision surprised colleagues and would-be rivals in the New Territories East constituency, where seven seats are up for grabs. One analyst suggested that officials from the central government's liaison office might have had a hand in Mr Chu's decision to boost the chances of pro-government parties. Academics believe more candidates with marginal support will withdraw from the fray in the coming weeks to avoid diluting the vote of their allies in the September polls. Recent opinion polls by Civic Exchange and the University of Hong Kong's Public Opinion Programme put support for Mr Chu at 3 per cent, the lowest in the constituency. Mr Chu's office said the lawmaker left Hong Kong yesterday morning to attend to matters on the mainland. Staff members were unable to shed any light on his sudden withdrawal. Elected twice by the Election Committee, the Hong Kong Progressive Alliance legislator had been actively campaigning for election in New Territories East. In his brief statement, Mr Chu, 60, cited personal reasons for dropping out of the contest. 'I will continue my job as a deputy to the National People's Congress,' he said. Fellow party legislator Tang Siu-tong said he was shocked by the news. 'We were discussing his campaign in New Territories East [on Saturday]. His support rating has been on the increase,' Dr Tang said. Political analyst Li Pang-kwong said he believed that officials from the central government's liaison office had been co-ordinating the lists to avoid clashes of support. 'It's no surprise that those with little support will be talked out of the battle,' he said. But he believed Mr Chu's withdrawal would have little impact on the result in New Territories East. Ma Lik, chairman of the Democratic Alliance for Betterment of Hong Kong, dismissed claims that the liaison office had been working behind the scenes. Andrew Cheng Kar-foo of the Democratic Party - who heads the list of the pan-democratic camp in New Territories East - said the change might have an effect on James Tien Pei-chun of the Liberal Party and Andrew Wong Wang-fat. He expressed concern that democratic development would be affected if more pro-Beijing hopefuls shied away from direct elections. Mr Tien believed he would benefit from the withdrawal because he and Mr Chu shared a business background.