* Occupy group says won't accept failure in road to democracy
* Plans protests against Beijing decision on format of HK poll
* Ex-governor Patten says UK has obligations to honour agreement (Adds Chris Patten letter, Macau poll)
By Anne Marie Roantree and Clare Baldwin
HONG KONG, Sept 3 (Reuters) - Hong Kong activists threatening to blockade the financial district in protest against China's curbs on democracy said Beijing had "brutally strangled" their hopes but that they would persevere with the struggle.
Hong Kong is bracing for a wave of protests after Beijing on Sunday ruled out fully democratic elections for the city's leader in 2017, sparking a political showdown with democrats.
Police on Monday used pepper spray to disperse activists who heckled and jeered a senior Chinese official who flew to Hong Kong to explain the decision by China's National People's Congress Standing Committee.
"Our target is a 2017 chief executive election that meets international standards. Although this target has been brutally strangled by the National People's Congress Standing Committee, the significance of our movement will not end at this point," the Occupy Central with Love and Peace movement said in a statement emailed to reporters on Tuesday.
"We Hongkongers won't accept failure in our road to democracy."
The group has threatened to lock down the former British colony's financial district on an unspecified date unless China grants full democracy, a proposal many business leaders have said could undermine the stability and development of the city.
Hong Kong people are split on the issue of street protests and the Occupy movement has not yet won broad support among the city's middle class, who are concerned about antagonising China and disruptions to business.
Bloomberg on Tuesday quoted Occupy Central founder Benny Tai as saying support for the group had dwindled, but Occupy said that was not the case.
"It is not correct to say that we have less support from the community after Beijing has made the decision," the statement said. "Although some pragmatic supporters may leave, new supporters are joining us because they are angry about the Chinese government's decision."
Hong Kong returned to China in 1997 with the promise of wide-ranging freedoms and autonomy not permitted on the mainland, but Communist Party leaders in Beijing fear calls for democracy could spread to cities on the mainland.
Hedge fund manager Edwin Chin, one of the financial sector's prominent supporters of Occupy, urged Hong Kong people to continue to rally for democracy.
"If people do not fight, it will get worse. Democracy in Hong Kong is difficult, but I do not lose hope. I hope the next generation can (make it come true)," he said.
Chin told Reuters on Tuesday that a leading business newspaper had dropped his long-running column, branding it a "political decision".
Chris Patten, the British governor of Hong Kong who cried during the 1997 handover ceremony, said Britain had a moral and political obligation to ensure China respects its commitments.
"We have a huge stake in the wellbeing of Hong Kong, with a political system in balance with its economic freedom," said Patten in a letter to the Financial Times.
His letter came a day after Britain's parliament said it had rejected Chinese calls to scrap an inquiry into Hong Kong's progress towards democracy.
Britain made no mention of democracy for Hong Kong until the dying days of more than 150 years of colonial rule.
Occupy has launched a campaign of civil disobedience, calling for full democracy with an unofficial referendum, marches and sit-ins. There have been clashes with police.
Beijing has responded by saying Hong Kong is a special administrative region of China, subject to Communist Party rule. Beijing has said it will permit a vote for Hong Kong's next chief executive, but only among a handful of pre-screened candidates.
An unofficial poll in the nearby southern Chinese gambling hub of Macau showed 89 percent of nearly 9,000 people who took part don't trust their leader.
Activists in the former Portuguese territory, which returned to China in 1999, have become increasingly vocal, with more than 20,000 people protesting in May against perceived inequalities and poor public services. (Additional reporting by Farah Master, Diana Chan and Dancy Zhang; Editing by Nick Macfie)