The people of Zurich voted on Sunday on a proposal to downgrade ties with its Chinese sister city, Kunming - a move which could strain relations between Switzerland and China.
The vote was called by two members of the right-wing Swiss People's Party.
They came out against a move by the city parliament to cut Zurich's annual credit to Kunming from SFr2.4 million to SFr.1.3 million next year, saying funding should be stopped altogether.
Since the sister city agreement was reached in 1982, Zurich has provided funding and know-how to improve Kunming's water resources and treatment, and has helped set up a traffic system which allows for a separate bus lane - a first in China.
However, Zurich's close links have come under increasing criticism mainly because of apparent financial and legal irregularities, which have been the subject of lengthy debate in the city government and parliament.
Most analysts say the people of Zurich will vote in favour of reducing the credit rather than stopping it altogether.
Local government leaders have warned that any move to end the sister city agreement could have serious implications for Switzerland's relationship with China.
swissinfo with agencies