In Geneva, unions and left-wing parties have submitted over 8,000 signatures to force a referendum against a new law allowing stores to open two Sundays a year.
Only 4,200 signatures were needed, giving the referendum committee a strong margin, said Unia's Yan Giroud. A vote could take place in November.
Opponents argue Sunday openings would worsen already difficult conditions for retail workers.
Supporters say the change would help local shops compete with French retailers and online sales.
But the left insists the real issue is household purchasing power, not opening hours. Geneva has voted on similar Sunday trading proposals several times before.
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