HONG KONG » An unauthorized addition to a luxury house may be sinking the hopes of the man thought to be China’s favorite to be Hong Kong’s next leader.

Henry Tang, a former senior government official, is facing increasing pressure to end his campaign to become chief executive, Hong Kong’s top government position.

Long seen as the candidate favored by Beijing, Tang has seen his popularity plummet over months of missteps, capped last week when he acknowledged that structures built at his wife’s home did not have government approval. Tang insists on continuing his candidacy, but the unauthorized construction, a favorite topic in local media coverage of public figures, was seized on by his political opponents.

"I don’t think he can hope to salvage his credibility," said Alan Leong of the Civic Party. "If he can’t handle his own affairs, how can he run a government?"

The scandal has provided more than just tabloid headlines. Political observers say the concerns dogging Tang reveal a growing public frustration that the local political and economic system is ruled by a small elite out of touch with the rest of the population. Tang’s candidacy, analysts add, also suggests a need to rethink the vetting process for candidates, and has fueled a growing local anxiety over Hong Kong’s relationship with mainland China.

The challenge facing all Hong Kong candidates "is whether they can be seen defending Hong Kong’s interests and autonomy," said Jean-Pierre Cabestan, head of government and international studies at Hong Kong Baptist University. "One of the themes of the campaign should be addressing social inequalities and creating a fair competition law. I don’t know if there’s anyone willing to fight these forces, any politician with the courage to speak out."

This year’s election for Hong Kong chief executive was expected to be like previous campaigns since the territory was returned to China in 1997, a buttoned-down affair that would have little drama. A 1,200-person election committee representing various business and social constituencies across Hong Kong will elect the chief executive on March 25. The majority of the committee’s members are seen by many political observers and academics as taking their cues from Beijing as to whom to support.

Both Tang and his main rival in the campaign, CY Leung, a former convener of Hong Kong’s Legislative Council, are viewed as acceptable candidates by the establishment in Beijing. A third candidate, Albert Ho of the Democratic Party, is seen as having little chance of winning the election.

Last week, Tang labored to explain the structures built at the home owned by his wife. Local news reports said that one of them, a basement occupying 2,200 square feet, or roughly 200 square meters, contained features like a wine cellar, a home movie theater and a Japanese-style bath. Tang has rejected those claims and said the basement was used as a storage space. He said his wife had carried out the work without his knowledge.

But the reported extravagance and Tang’s explanation, seen by many as shifting blame onto his wife, have sharply influenced public opinion. A poll conducted by the University of Hong Kong showed that most people surveyed doubted the integrity of Tang, the 59-year-old scion of a wealthy family from Shanghai. The poll was published by The South China Morning Post over the weekend.

The sagging ratings culminate months of gaffes by Tang, who last September resigned as chief secretary, the government’s No. 2 position, to run for chief executive. In October, amid public speculation about an extramarital affair, he acknowledged simply that he had made a mistake in his romantic life.

Last May, Tang said Hong Kong’s youth should try to emulate Li-Ka-shing, Hong Kong’s wealthiest tycoon, rather than complain about the growing gap between the rich and the middle class. The remarks were made during a year in which Hong Kong residents staged several demonstrations to protest housing prices and what they have called an economic system run by a small group of wealthy individuals.

Analysts say those protests were part of a larger movement reflecting growing frustration among Hong Kong residents over their voice in the political system and access to housing and public services.

"In Hong Kong, you have a coterie of people who are rich and powerful," said Michael DeGolyer of the Hong Kong Transition Project, an independent research organization. "You have a rigged economy that is full of cartels, not truly open and competitive. People are concerned by that."

That sense of frustration has spilled into public perceptions of mainland China. Many observers say Hong Kong residents fault people from the mainland for driving up the costs of housing and clogging public services. The number of mainland women coming to Hong Kong to give birth has grown so dramatically that the local government placed a cap on how many pregnant mainland women are allowed into hospitals.

Surveys by both the Transition Project and the University of Hong Kong have shown that a growing number of people identify themselves as Hong Kong residents rather than Chinese. Such studies do not surprise local analysts and politicians, who say the existing system for choosing Hong Kong’s chief executive presents many challenges for mainland China’s leadership.

"Beijing has to be careful," said Cabestan of Hong Kong Baptist University. "Local society is more frustrated than ever, and an increasing number of people feel sidelined by the mainland nouveaux riches coming here."

Added Leong of the Civic Party: "The cultural differences between Hong Kong and the mainland have not been properly addressed for the past 15 years," a reference to the period since the territory’s handover to China. "Beijing should bring some humility when dealing with Hong Kong."