Left wing groups are threatening to ignore the 100-person demonstration limit and take to the streets on Saturday, May 1st – Labour Day.
Most trade unions and left-wing political parties are not marching to respect the law, but those on the more extreme side say they will be holding protests.
Websites run by anarchist and communist groups say they will wear masks, disinfect their hands and stay home if they test positive.
But groups, mainly in Zurich and Bern, say the limit on the number of people is designed to restrict political expression.
Police in both cities are staying silent on what their response could be.