Hong Kong's oldest and most politically influential student body, which organised the sit-ins that acted as a catalyst for last year's Occupy turmoil, suffered the most significant split in its 57-year history yesterday when one of its biggest bloc of members voted to leave. University of Hong Kong students voted narrowly in favour of quitting the Hong Kong Federation of Students in a referendum sparked by a groundswell of support for the so-called localist movement, which to varying degrees supports Hong Kong independence and believes the federation's core mission to "build a democratic China" diminishes its ability to represent the interests of the city. The referendum took place amid concerns of possible tension between local and mainland students on campus. This month a state-backed newspaper claimed there was a "McCarthyite trend" of criticism against mainland student Eugenia Yip, who was running in student-union elections at the university. Yip lost her bid to become the union's social secretary yesterday. The Global Times was referring to Joseph McCarthy's infamous anti-communist crusades in 1950s America. Yip did not respond when approached for comment. Calls to leave the federation have been mounting since the Occupy protests against Beijing's restrictions over Hong Kong's constitutional reform late last year, with some students disgruntled by the federation's handling of the sit-ins. HKU students Alex Chow Yong-kang and Yvonne Leung Lai-kwok were among the leaders of the movement. Economics undergraduate Keyvin Wong Chun-kit, former deputy chief editor of student magazine Undergrad , was a key campaigner for the ballot. Wong also co-authored a book that Chief Executive Leung Chun-ying lambasted in his policy address last month for "advocating independence" and "putting forward fallacies". A concern group founded by Wong and others had argued that a split would free the HKU student union from being bound by the federation's China platform. More than 6,000 HKU students voted, with 2,522 in favour of leaving the federation and 2,278 against. There were 1,293 abstentions. "We expected the motion to be passed, although our cabinet opposed it. We respect the members' decision," said Billy Fung Jing-en, the student union's newly elected president. Fung said the union had always made Hong Kong issues its priority and said it would continue holding events to mark the anniversary of the June 4 Tiananmen crackdown. The referendum drew a 39 per cent voter turnout - the highest of all polls conducted by the union in the past five years. A previous bid by the HKU student union to leave the federation failed in 2006 even though there were more in favour than against, as the ballot did not reach the quorum of 10 per cent. Tommy Cheung Sau-yin, president of the Chinese University student union, who sits on the federation's standing committee, said the loss of the HKU students would weaken its position, but would not affect the student democracy movement as a whole.