On 22 September, the Spanish Congress’s Foreign Affairs Committee rejected the motion calling on the government to begin the process of joining the Treaty on the Prohibition of Nuclear Weapons. SUMAR’s proposal was supported by Podemos, ERC and EH Bildu. The Socialist Party (PSOE) and Junts abstained, while the PP and Vox voted against it.
The vote did not decide whether Spain will join the treaty: it was a vote on a parliamentary call for the government to start that process. But the result is a missed opportunity to act on the support for joining expressed by 80% of Spaniards in ICAN’s May 2026 poll. Spain can still choose to sign the TPNW, and ICAN and its partners will continue to urge the government to do so.
A government that has already said yes, in everything but ink.
Prime Minister Pedro Sánchez has not been shy about where he stands. At the Munich Security Conference in February 2026, he delivered what may have been the most forceful statement by any NATO head of government on nuclear weapons in years, calling nuclear deterrence not a guarantee of security but "a roulette." He called on nuclear-armed states to halt their rearmament.
This was not a new position. In 2018, Sánchez publicly committed to signing the TPNW. That commitment has never been withdrawn and now is the time to fulfil that promise.
No legal obstacle. No NATO obstacle.
One of the most persistent myths about the TPNW is that NATO membership makes it impossible to sign. Spain's case exposes that argument for what it is: a mere political choice, but definitely not a legal constraint.
Spain's penal code has prohibited nuclear weapons as weapons of mass destruction since 2015. A national referendum in 1986 rejected the stationing of nuclear weapons on Spanish soil. Joining the TPNW would simply formalise in international law what is already national law and the expressed will of the Spanish people.
NATO's 2010 Strategic Concept, which promotes nuclear deterrence, is a political document, not a binding treaty. It creates no legal obligation to possess, endorse, or rely on nuclear weapons. Spain's actual alliance commitments, its troops, its missions, its spending, its integrated command, would remain entirely intact. The alliance does not require unanimity on nuclear doctrine.
The TPNW is a mechanism by which Spain can fulfill obligations under the Nuclear Non-Proliferation Treaty. The two treaties complement one another. The TPNW itself recognises the NPT as the cornerstone of the disarmament and non-proliferation regime, and provides the concrete legal path for implementing Article VI of the NPT, the disarmament obligation that nuclear-armed states have been deferring for more than fifty years.
A country and a civil society already leading.
The Spanish public is among the most anti-nuclear in Europe, and civil society has been making that visible.
132 Spanish cities and municipalities have now signed the ICAN Cities Appeal, formally urging the national government to join the TPNW. Mayors and local councillors from across the political spectrum, many from the Prime Minister's own Socialist party, have signed. The demand for joining the TPNW is deeply rooted in local communities across the country.
The Alianza por el Desarme Nuclear, a coalition of 65 Spanish civil society organisations, has spent months laying the groundwork: building the political case, answering objections, and making clear to parliamentarians that this is achievable, lawful, and overdue – and supported by a vast majority of Spain's population – as confirmed by ICAN's representative poll conducted by Yougov from May this year.
What comes next?
The committee’s rejection does not close the door to Spain joining the TPNW. The decision to pursue accession remains with the Spanish government, and the public support, civil society mobilisation and case for joining described above remain.
The TPNW’s First Review Conference later this year offers Spain another opportunity to engage with the treaty. ICAN calls on the government to attend and to set out a clear path towards joining.