Zurich is to do away with tax privileges for wealthy foreigners, a policy which has attracted a host of super-rich celebrities to the canton.
On Sunday voters unexpectedly endorsed a proposal by centre-left political parties to abolish lump sum taxation.
Nearly 53 per cent of voters came out in favour of scrapping tax perks – in the first ballot held on the issue.
Proponents of lump sum tax argued Zurich stood to lose revenue to other cantons. Opponents took issue with different legal standards for the wealthy and the less well-off, for Swiss and for foreigners.
Some 137 foreign residents are taxed at a flat tax rate in the Zurich region.
In 2006 more than 4,100 wealthy foreigners across Switzerland benefited from special tax arrangements.