Question to the Foreign, Commonwealth & Development Office:

To ask the Secretary of State for Foreign, Commonwealth and Development Affairs, for what reason the UK is not a signatory to the UN Treaty on the Prohibition of Nuclear Weapons which came into force on 22 January 2021; and what strategy his Department has for the (a) reduction of the UK's nuclear arsenal and (b) prevention of a new arms race.

The UK is fully committed to the long-term goal of a world without nuclear weapons. The best way to achieve this is through gradual multilateral disarmament negotiated using a step-by-step approach, under the framework of the Nuclear Non-Proliferation Treaty (NPT). The Government has been clear it will not sign the Treaty on the Prohibition of Nuclear Weapons (TPNW). We do not believe this Treaty will bring us closer to a world without nuclear weapons. The UK has unilaterally reduced its nuclear forces significantly from their Cold War peak. We possess the smallest nuclear warhead stockpile of the five Nuclear Weapons States (NWS) recognised under the NPT, and are the only NWS to have reduced its deterrent capability to a single nuclear weapon system. We welcome the US and Russia's joint statement on strategic stability on 16 June 2021 and their commitment to a bilateral strategic stability dialogue. We regard this as a serious signal of intent to reduce the risk of nuclear conflict and enhance mutual trust and security by the two countries, which hold almost 90% of the world's nuclear weapons.