The Government has equivocated about whether it would attempt to enforce the International Criminal Court (ICC) arrest warrant against Prime Minister Netanyahu. This paper shows that any such attempt would be clearly unlawful. The International Criminal Court Act 2001 carefully preserves the immunity of the Head of Government of a State that is not party to the Rome Statute that established the ICC. The only exceptions are if the State waives immunity or the UN Security Council adopts a resolution. Israel is not a party to the Rome Statute and there is no UNSC resolution. It would therefore be unlawful as a matter of UK domestic law and international law for the Government to attempt to arrest Prime Minister Netanyahu. The Government should make clear that it does not accept that there has been any relevant change in international law in relation to the state or diplomatic immunity of a Head of Government, or Head of State, of a State that is not party to the Rome Statute.