The protest snarled traffic in the Paris area from daybreak to nightfall, as farmers from across the country attempted to use 1,000 tractors to block off access to Paris. It was among several recent farmer protests around Europe driven by growing concerns about maintaining European agricultural traditions and standards.

The tractors will remain parked on the highway circling the city until French President Emmanuel Macron agrees to meet with protesters, regional farmers’ union spokesperson Elisa Despiney told The Associated Press.

They could remain there for “hours, or maybe days,” she added.

By mid-morning, blue and green tractors bearing signs reading “Respond, Macron!” had advanced toward the southwestern edge of the city, taking up two lanes of the highway as police escorted them on motorcycles. They then stalled on the Paris ring road, where some protesters pitched tents and lit fires.