The 2027 vote: new nuclear power plants in Switzerland

What Parliament decided on 19 June 2026

Since 2017, Article 12a of the Nuclear Energy Act (KEG) has banned the construction of new nuclear power plants in Switzerland. On 19 June 2026 Parliament deleted this article. New nuclear power plants – usually called “new AKW” in the Swiss debate – may therefore be planned and licensed again, to replace the existing reactors that will leave the grid in the coming decades – or in addition to them if electricity demand grows. The law does not cap the number of new plants.

The amendment does not decide on the construction of any particular plant. It only lifts the ban. Every new plant still needs a general licence from the Federal Council and Parliament, against which a referendum can again be called, plus construction and operating licences and the safety review by the Swiss Federal Nuclear Safety Inspectorate ENSI.

The referendum against the “nuclear law”

An alliance of anti-nuclear organisations, environmental groups and political parties has called a referendum against the amendment to the Nuclear Energy Act; the opponents call the bill the “Atom-Gesetz”. A referendum requires 50,000 valid signatures within 100 days; the alliance reported more than 125,000 signatures collected on 20 September 2026 and submitted them to the Federal Chancellery on 6 October 2026. Once the Federal Chancellery confirms that the referendum is valid, the Federal Council sets the voting date – 28 February 2027 at the earliest.

What Switzerland is voting on – and what it is not

• Yes means: the construction ban is lifted. Switzerland keeps the option of replacing its existing nuclear power plants with modern reactors or building additional ones. Whether, where and when anything is built is decided by the ordinary licensing procedures – with democratic participation.
• No means: the 2017 ban stays. When today’s plants close, around one third of Swiss electricity production disappears, and winter supply depends more heavily on imports and gas-fired plants.
• Not on the ballot are the continued operation of the existing plants, deep geological disposal (the Nördlich Lägern procedure runs until around 2031, with a possible popular vote of its own) or any specific construction project.

Why this is about more than electricity

Three questions hang on this vote. Economy: industry, data centres and the electrification of heating and transport need reliable, affordable electricity – in winter too. Sovereignty: a country that must import more and more of its winter electricity depends on its neighbours’ power plants and prices. Nuclear fuel, by contrast, can be stockpiled for years thanks to its enormous energy density – impossible with gas or electricity. Climate: nuclear energy delivers practically CO₂-free baseload power regardless of weather and season, complementing hydropower and renewables on the way to net zero by 2050.

The no campaign’s claims, fact-checked

The “Nein zu neuen AKW” campaign works with seven core claims. WePlanet and the Anthropocene Institute have examined them in the report “Yes to new nuclear power plants”:

• “The parliamentary decision goes against the will of the people” – only the 2017 vote concerned nuclear power directly; today a majority supports lifting the ban.
• “New nuclear plants make Switzerland dependent on foreign countries” – uranium comes from Kazakhstan, Canada, Namibia and Australia; it is giving up nuclear that creates dependence: up to 12.4 TWh of winter imports.
• “The Swiss way with solar, wind and hydro is already a success” – even today Switzerland covers its winter demand only with imports.
• “Nuclear waste is an unsolved problem” – in 2024 Nagra submitted the application for the deep geological repository at Nördlich Lägern.
• “New nuclear plants are too expensive” – around CHF 17.25 billion for a new plant, not 25, and less support per megawatt-hour than alpine solar.
• “New nuclear plants are too dangerous” – Generation 3+ reactors have an accident probability around 100 times lower.
• “Net zero by 2050 works without nuclear” – only with winter imports whose availability and cleanliness Switzerland does not control.

All chapters with sources: read the fact check · report as PDF

Timeline to the vote

• 19 June 2026: Parliament lifts the construction ban (amendment of the Nuclear Energy Act).
• 30 June 2026: the “Nein zu neuen AKW” alliance launches the referendum.
• 20 September 2026: the alliance reports more than 125,000 signatures collected.
• 6 October 2026: submission of the signatures to the Federal Chancellery.
• 28 February 2027 at the earliest: popular vote on the amendment of the Nuclear Energy Act – the Federal Council sets the date.

Want to support the campaign? Here is how to get involved.

Frequently asked questions about the vote

When does Switzerland vote on new nuclear power plants?

On 28 February 2027 at the earliest, the first federal voting Sunday of the year. The referendum against the amendment of the Nuclear Energy Act was submitted on 6 October 2026 with more than 125,000 signatures; the Federal Council sets the date once the Federal Chancellery has confirmed that the referendum is valid.

What is the “nuclear law” (Atom-Gesetz)?

This is what the opponents call the amendment of the Nuclear Energy Act of 19 June 2026, with which Parliament lifted the ban on new nuclear power plants in force since 2017. Officially it is a partial revision of the Nuclear Energy Act (KEG).

What changes with a yes?

The construction ban is lifted. New nuclear power plants may be planned and licensed again – to replace the existing plants or in addition to them. But every project still needs a general licence from the Federal Council and Parliament, construction and operating licences and the ENSI safety review. No plant is built automatically because of the vote.

What changes with a no?

The 2017 ban remains. Today’s nuclear power plants, which supply around a third of Swiss electricity, could not be replaced. Winter supply would then depend more heavily on electricity imports and gas-fired plants.

Who is behind the referendum, and who is behind the yes campaign?

The referendum is carried by the “Nein zu neuen AKW” alliance of anti-nuclear organisations, environmental groups and parties. The “Yes to Nuclear” campaign is run by WePlanet DACH, based on the report by WePlanet and the Anthropocene Institute and supported by organisations such as Voices of Nuclear Switzerland.