HONG KONG (Reuters) - Hackers have disabled an independent Hong Kong “civil referendum” aimed at gauging how people might have voted if allowed in a scandal-laced, undemocratic leadership election on Sunday, the director of the initiative told reporters on Friday.

The Hong Kong chief executive will be chosen by a 1,200-strong election commission, stacked with Beijing loyalists, as public frustration grows over the two leading candidates amid a series of highly publicized scandals.

Hong Kong’s seven million people have no say in their choice of leader. The territory returned to Chinese rule in 1997 with the British pushing China to grant it democracy, despite offering no such luxury themselves during over 150 years of colonial rule.

The University of Hong Kong’s “civil referendum” was launched to gauge how the people might have voted if given a choice.

It allowed people to vote by mobile phone or the Internet on the website (popvote.hk/) and operated normally when it opened on Thursday but then crashed given what Robert Chung, the director, called "high-level cyber attacks" that crippled servers.

“We do not quite understand the motive,” Chung told reporters.

Chung’s polls have in the past triggered the ire of mainland Chinese media outlets and officials. A December poll on the extent to which Hong Kong people identified themselves as Chinese citizens dropped to 17 percent, the lowest level in 12 years.

Chung was subsequently denounced by a mainland propaganda official in Hong Kong while mainland media accused Chung of fomenting unpatriotic sentiment and of having “evil” political aims.

Chung said around 14,000 responses had been received in the civil referendum. Despite the technical difficulties, he said he was hopeful of 100,000 eventual responses.

“We hope we can preserve this opportunity for people to vote,” Chung added.

Textiles tycoon and former senior official Henry Tang was once widely considered Beijing’s preferred candidate for the top job, but political sources and the media have suggested a shift in allegiance to his rival, Leung Chun-ying.

Tang has been tarnished by an illegal construction scandal and self-confessed marital infidelities, while Leung faces a conflict of interest probe connected to a construction project and accusations of running a dirty election campaign.

With China facing a critical leadership transition later in the year, scandals are an unwelcome distraction in the small but influential city whose moves towards full democracy have antagonized China’s Communist leaders since 1997.