Hong Kong residents have the least confidence about the future in 25 years, amid rising levels of distrust between the local and central government, according to a survey.

The results, published by the University of Hong Kong's Public Opinion Programme on Tuesday, come amid rising concerns over what's been seen as threats to local autonomy — famously guaranteed for 50 years by China under the "one country, two systems" arrangement.

Hong Kong, a former British colony, has since 1997 been a Special Administrative region of China. The central government in Beijing is responsible for defense and foreign affairs, while Hong Kong has wide autonomy in other areas.

The territory of about 7.4 million people has its own laws and currency, while traditions of transparency, low taxes and light regulation have helped make it a major global financial center.

But the electoral system makes it virtually impossible for its chief executive, Hong Kong's top official — to be unpalatable to China.

The telephone survey — conducted from Feb. 28 to Mar. 5 — found that 39 percent of respondents expressed confidence in Hong Kong's future, while 55 percent said they were not confident.

That resulted in a "net confidence" reading of minus 16 percent, the worst recorded since polling began 25 years ago in 1994, it said.

The survey contacted 1,024 local residents, aged 18 or above, who speak Cantonese — the predominant local language. It received responses from 72.2 percent, and did not seek reasons for the answers given.