Question to the Ministry of Defence:

To ask the Secretary of State for Defence, what the Government’s policy is on the use of nuclear weapons in retaliation to non-nuclear strategic attacks.

As set out in the 2015 Strategic Defence and Security Review, we continue to keep our nuclear posture under constant review in the light of the international security environment and the actions of potential adversaries. We remain deliberately ambiguous about precisely when, how and at what scale we would contemplate use of our nuclear weapons, in order not to simplify the calculations of any potential aggressor and in order to protect our national security.