Hong Kong's leader refused to meet with pro-democracy demonstrators by their midnight deadline Tuesday, despite their threats to expand the protests that have clogged the streets with tens of thousands of people in the stiffest challenge to Beijing's authority since China took control of the former British colony in 1997.
Protesters counted down to midnight and cheered as the deadline passed, but took no immediate action.
Meanwhile, Britain's deputy prime minister, Nick Clegg, said Tuesday that he had summoned the Chinese ambassador to discuss the dispute, saying it was essential that Hong Kong's people have a genuine right to choose their top leader.
"I am extremely concerned about the recent events in Hong Kong. Britain and China have solemn obligations to the people of Hong Kong to preserve their rights and freedoms," Clegg said in a statement.
China took control of Hong Kong under a "one country, two systems" arrangement that guaranteed the seven million residents of the city semi-autonomy, Western-style civil liberties and eventual democratic freedoms that are denied to Chinese living on the communist-ruled mainland.
The protesters want a reversal of a decision by China's government to screen all candidates in the territory's first direct elections, scheduled for 2017 – a move they view as reneging on a promise that the chief executive will be chosen through "universal suffrage."
Hong Kong Chief Executive Leung Chun-ying's rejection of the student demands dashed hopes for a quick resolution of the five-day standoff that has blocked city streets and forced some schools and offices to close.
It was unclear what action the demonstrators would take next. There were no immediate speeches or official statements from the protesters, who chanted "Jiayou! Jiayou!" – or "Keep it up!" – while waving their cellphones with the LED flashlights sparkling in the dark.
Earlier Tuesday, Alex Chow, secretary-general of the Hong Kong Federation of Students, the organizer of the university class boycotts that led to the street protests, said the students were considering various options if their demands were not met, including widening the protests, pushing for a labour strike and occupying a government building.
As concern mounted over how the standoff might eventually end, Chinese President Xi Jinping, who has taken a hard line against any perceived threat to the Communist Party's hold on power, vowed in a National Day speech to "steadfastly safeguard" Hong Kong's prosperity and stability.
China's government has condemned the student-led protests as illegal, though so far it has not overtly intervened, leaving Hong Kong authorities to handle the crisis.
Despite the hardening rhetoric from both sides, the mood Tuesday night was festive. Few police were evident, and those who were present appeared relaxed. The crowds were expected to grow, with most people off work both Wednesday and Thursday for public holidays.
Both sides appeared to be waiting out the standoff, as police continued the light-handed approach to the protests they adopted after their use of tear gas and pepper spray over the weekend failed to drive out tens of thousands of people occupying streets near the government headquarters. The sit-ins instead spread to the financial district and other areas.
"We are not afraid of riot police, we are not afraid of tear gas, we are not afraid of pepper spray. We will not leave until Leung Chun-ying resigns. We will not give up! We will persevere until the end!" Lester Shum, another student leader, shouted to a crowd at Admiralty, near Hong Kong's waterfront.
Leung's blunt rejection of the demands from the students was not surprising. China's Communist leadership is wary of any conciliatory moves that might embolden dissidents and separatists on the mainland.
Occupy Central, a wider civil disobedience movement, said in a tweet that the pro-democracy protesters were demanding genuine democracy and Leung's resignation. It said it would "announce new civil disobedience plans" on Wednesday.
Hong Kong's free press and social media give the protesters exposure that may help prevent China from cracking down in the same way it has on restive minorities and dissidents living in the mainland, where public dissent is often harshly punished.
The protests have been dubbed the "Umbrella Revolution" by some because the crowds have used umbrellas to block the sun and to deflect police pepper spray.
"We are really basically just calling for the government to speak with us but they've been mute," Peter Chin, a 22-year-old student at Hong Kong University. "We'll keep staying here until they're ready to consult with us."
Elaine Kurtenbach, Louise Watt and Kelvin Chan in Hong Kong and Aritz Parra in Beijing contributed to this report.