More than 2,000 marched in Geneva on Saturday demanding better working conditions.
The march was one of a series across the country.
Although it was aimed at helping all workers, it was mainly the construction sector which made up most of the protestors.
New talks are due as several existing agreements covering building work are set to expire.
Unions are calling for pension protection, better pay and bad weather allowances.
Overall, the march was described as good natured.
It brought the Mont-Blanc Bridge to a standstill in the middle of afternoon as people stopped to listen to speeches.
More from Bitesize News
Geneva airport travel landmark
For the first time in Geneva Airport's history, more passengers are flying to and from China than to and from the United States
Desalpes festivals underway in the mountains
Summer droughts have forced many Swiss cattle herders down from Alpine pastures earlier than usual, but the traditional désalpes will still take place across Romandy this autumn
Nuclear power vote imminent
Switzerland is heading to the polls on nuclear power after opponents gathered more than 125,000 signatures in just three months
High rise buildings the future
Geneva's chronic housing shortage is pushing developers to build up — literally, by adding storeys to existing buildings
Weekend protests in Geneva and Lausanne
Thousands of people marched in Geneva and Lausanne on Saturday to demand action on climate change after the summer's heatwaves
Bank details compromised
British digital bank Revolut has admitted handing customer information to fraudsters who impersonated a European government agency