As the Integrated Review of Security, Defence, Development and Foreign Policy makes clear, the UK would only consider using nuclear weapons in extreme circumstances of self-defence, including the defence of our NATO Allies. While the UK’s resolve and capability to use our nuclear arsenal, if necessary, is beyond doubt, it makes sense for the UK to remain deliberately ambiguous about precisely when, how, and at what scale the use of nuclear weapons would be contemplated.

That said, the UK has committed not to use, or threaten to use, nuclear weapons against any non-nuclear weapon state party to the Treaty on the Non-Proliferation of Nuclear Weapons 1968. However, assurance rightly does not apply to any state in material breach of those non-proliferation obligations.

Indeed, the UK takes its responsibilities as a nuclear weapon state seriously and will continue to encourage other states to do likewise. The avoidance of war between Nuclear-Weapon States and the reduction of strategic risks are HM Government's (HMG) foremost responsibilities. In line with this, it will always endeavour to do everything in its power to reduce the likelihood of nuclear conflict, including resolving issues peacefully and diplomatically wherever possible.

I share HMG’s firm belief that the best way to achieve our collective goal of a world without nuclear weapons is through gradual multilateral disarmament negotiated using a step-by-step approach, under the framework of the Nuclear Non-Proliferation Treaty.

HMG has been clear that President Putin’s comments regarding nuclear weapons are irresponsible. No other country is talking about nuclear use, and HMG does not see the conflict in Ukraine as a nuclear crisis. Putin's nuclear sabre-rattling is designed to distract us from our efforts in Ukraine, and it will not work.

Any use of nuclear weapons would break the taboo on nuclear use that has held since 1945 and would, of course, lead to severe consequences for Russia. This has been conveyed to the Russian regime in no uncertain terms, as has our demand that Putin steps back from this dangerous nuclear rhetoric.