Many of Switzerland's foreign millionaires will be watching nervously on Sunday as voters decide whether to scrap one of the country's biggest tax perks for expatriates.
Switzerland's system of charging foreign residents with no gainful activity in the country a lump sum based on their living expenses, instead of taxing assets or income, has helped make it a popular home for the super rich.
Five Swiss cantons, including Zurich, have abolished the lump-sum tax, but the left-wing Social Democratic Party gathered the necessary 100,000 signatures to force a vote on doing away with it at the national level.