Hong Kong residents’ disapproval of the “one country, two systems” system that gives their city autonomy from China rose to the highest level since before the territory reverted to Chinese rule in 1997, a poll showed.

Some 47.2 percent of people participating in the poll said they weren’t confident in the arrangement, compared to 47.1 percent who said they were, the highest level of dissatisfaction since 1994, according to today’s survey by the Public Opinion Program at Hong Kong University.

The survey was carried out June 10-13, around the time news broke that former National Security contractor Edward Snowden had fled to Hong Kong and revealed a secret U.S. surveillance program. While Hong Kong Chief Executive Leung Chun-ying said the city will handle any U.S. extradition request according to the law, the case has raised concern that China will dictate Snowden’s fate.

Thirty-two percent of respondents said they trusted the Hong Kong government, down 12 percentage points from a March survey, while 25 percent trusted the central government in Beijing, also a 12 percentage point decline.

Hong Kong’s residents enjoy civil liberties such as freedom of speech and freedom of assembly that people in the mainland don’t have. They were guaranteed those rights for 50 years from the 1997 handover from U.K. control.

The telephone survey of 1,055 people had a margin of error of plus or minus four percentage points.