Northern Ireland protocol: what is the ‘doctrine of necessity’?

The UK government hopes a little-known legal principle will overturn parts of the post-Brexit agreement

In justifying its attempt to unilaterally overturn parts of the post-Brexit agreement with the EU, the UK government has invoked a little-known legal principle known as the doctrine of necessity". The loophole is allowed by the UN's International Law Commission to be used by a state facing grave and imminent peril".

But the government's ex-legal adviser Jonathan Jones said the EU would find the use of the doctrine completely unpersuasive".