HONG KONG (REUTERS) - It was meant to be a major set-piece event, potentially the most important bill put to Hong Kong's legislature since the former British colony's 1997 handover to Chinese rule, but it ended in unscripted embarrassment for the pro-Beijing establishment.
For almost 20 months, lawmakers and officials in the financial hub tussled over a China-vetted electoral reform package that needed a two-thirds majority from the 70-seat chamber to pass.
The blueprint would have given every Hong Kong citizen a vote for the city's next leader in an election in 2017, but with only pre-screened, pro-Beijing candidates on the ballot.
The Legislative Council's 27 pro-democracy lawmakers had vowed to vote it down, while the remaining pro-Beijing lawmakers pledged to back it.
Over several minutes on Thursday, however, what was expected to be a carefully choreographed vote unravelled.
As the chamber chime began sounding for members to deliberate before casting their ballots, pro-Beijing lawmaker Jeffrey Lam requested a 15-minute delay, a request that was rejected by council president Jasper Tsang.
Soon afterwards, scores of pro-Beijing lawmakers abruptly walked out of the chamber, catching many by surprise.
"Because it came so suddenly our communication wasn't very good and there may have been some misunderstandings," said the head of the DAB, Hong Kong's largest pro-establishment party, Tam Yiu-chung.
"People wondered why we were walking out so some problems emerged. I myself have responsibility ... that a problem like this happened is something I deeply regret."
With most of the pro-Beijing lawmakers absent, the vote went ahead, with 28 votes against the package, and only eight for it, dealing a crushing symbolic defeat for the Beijing-backed plan.
Pro-Beijing lawmakers said afterwards that the walkout had been because one of their number, Mr Lau Wong-fat, had taken ill, and his colleagues left to try to delay the vote to allow him to return.
But a lack of co-ordination meant eight pro-Beijing lawmakers lingered in the chamber, meaning there were still enough legislators present for a quorum and the vote went ahead.
"It wasn't planned. It was just an accident,"pro-establishment lawmaker Abraham Shek said of the walk-out. "Somehow the others didn't realise what we were doing."
Hong Kong's leader Leung Chun-ying when questioned about the walkout repeatedly denied that some pro-establishment lawmakers may have wavered in their support for the package, saying their backing of electoral reforms had been steadfast.
While the unanimous opposition of the democrats in vetoing the package meant the result was not in doubt - the landslide defeat by 28 votes to 8 was an uncomfortable rebuff for Beijing's Communist Party leaders unused to such reversals.
It was a rare instance of a local-level legislature voting so heavily against a proposal endorsed by China's national legislature, The National People's Congress.
Political analyst Johnny Lau, who has close ties with several pro-Beijing politicians, said a few had expressed privately to him they were considering abstaining to bolster their prospects in the next city-wide legislative polls.
"Some of them told me that they planned this before. They were thinking about the legislative elections next year," Mr Lau said in a telephone interview.
"If they voted for the plan, then the democrats could use this as a reason to attack them, so they didn't want to leave a record."
Visibly subdued, pro-Beijing lawmakers told a news conference afterwards that they had already met with a deputy director of China's representative office in the city, the Liaison Office, to offer an explanation for the walk-out.
"If I were the China Liaison Office I wouldn't be happy either," said pro-establishment lawmaker and a Hong Kong deputy to China's parliament, Mr Michael Tien. "But what can they do? They will definitely not be happy."