The public consultation phase for CERN’s proposed Future Circular Collider project has begun in Switzerland and France, marking a major step in the long-running evaluation of what could become the world’s largest particle physics facility.
The consultations will run between May and October 2026 and are intended to gather public feedback before any final approval decision is made.
CERN confirmed that the Future Circular Collider remains under study, with a formal decision on whether to proceed not expected before 2028.
The project is currently being assessed as part of the wider update to the European Strategy for Particle Physics, which guides the continent’s long-term research priorities.
If approved, the Future Circular Collider would be built in a 91-kilometre underground tunnel beneath parts of eastern France and western Switzerland.
Scientists say the machine could unlock new insights into the structure of matter and the origins of the Universe, while also driving advances in engineering, computing and energy technologies.
What is the Future Circular Collider?
The proposed Future Circular Collider, often referred to as the FCC, would succeed CERN’s existing Large Hadron Collider near Geneva.
The new machine would sit around 200 metres underground, stretching beneath the French departments of Haute-Savoie and Ain, as well as the Swiss canton of Geneva.
Unlike the Large Hadron Collider’s initial focus on proton collisions, the first planned phase of the FCC would collide electrons and positrons. Researchers believe this approach could deliver far more precise measurements of fundamental particles, including the Higgs boson.
CERN argues that the Future Circular Collider could help answer unresolved questions in modern physics, including the nature of dark matter and the origin of the matter-antimatter imbalance in the Universe.
Switzerland launched earlier this month
In Switzerland, the public consultation process officially opened on 18 May 2026 and continues until 2 October. The discussions will be overseen by independent guarantors tasked with ensuring transparency and fairness throughout the process.
Residents will be able to participate through workshops, public discussions, guided tours and site visits linked to the Future Circular Collider proposal. CERN said the aim is to provide clear information while allowing local communities to raise concerns and ask questions directly.
The consultation forms part of a broader effort to maintain dialogue with residents after earlier engagement activities began in 2024.
France opens national bublic debate
In France, consultations on the Future Circular Collider will be held under the supervision of the Commission Nationale du Débat Public (CNDP), the country’s independent authority for major public infrastructure debates.
The French debate is scheduled to run from 2 June to 1 October 2026, with an opening meeting planned for 4 June. The process will include town hall meetings, workshops, round-table discussions and online participation.
French residents will have the opportunity to question CERN representatives and discuss how the project could evolve before any final decision is reached.
Decision expected no earlier than 2028
Despite the launch of the consultation phase, CERN stressed that the Future Circular Collider has not yet been approved. The project remains part of an ongoing scientific and political review involving CERN’s Member States.
The organisation’s governing council is expected to consider recommendations from the European particle physics community before determining whether construction should move forward.
If the project gains approval, the Future Circular Collider would become one of the most ambitious scientific infrastructure projects ever attempted in Europe, with construction and operation expected to span several decades.