The ballot concerned the popular initiative "No to a Switzerland with 10 million! (Sustainability Initiative)", according to the Federal Council. The government page said the initiative would have required Switzerland's population to remain below 10 million until 2050 and would have required the Federal Council and Parliament to take measures if the permanent resident population exceeded 9.5 million before then.
Table: Swiss population-cap referendum result
| Result item | Reported figure |
|---|---|
| No vote | 54.79% |
| Yes vote | 45.21% |
| Turnout | 58.86% |
Source: Guardian report of Swiss referendum result, June 14, 2026.
The Federal Council said Switzerland had about 9.1 million residents at the end of 2025 and that the population had grown by around 1.7 million since the introduction of free movement of persons in 2002. The same official explanation said that, if the 10-million threshold were exceeded, Switzerland would have had to terminate agreements contributing to population growth, including the agreement with the European Union on free movement of persons, after two years.
The legal effect would therefore have reached beyond a population target. The Federal Council said ending the free-movement agreement would also render the other Bilateral Agreements I null and void, while Switzerland's participation in the Schengen and Dublin arrangements would be called into question. Al Jazeera also reported that a yes vote could have forced restrictions on asylum and residency permits and affected Switzerland's EU free-movement agreement.
The proposal was backed by the Swiss People's Party, according to the Guardian and AP. The Guardian reported that the party argued the population cap was needed because population growth was putting pressure on infrastructure, housing, social programmes and natural resources. AP reported that the party framed the measure around population growth and migration from the European Union.