By Lord Verdirame KC and Richard Ekins KC (Hon)

In a paper published on 25 November 2024, we made clear that it would be unlawful for the British Government to attempt to arrest Prime Minister Benjamin Netanyahu of Israel pursuant to the arrest warrant that the International Criminal Court (ICC) issued on 21 November 2024. If the Government were to attempt to enforce the ICC arrest warrant, it would be acting beyond the scope of the powers conferred on it by the International Criminal Court Act 2001 and would be placing the UK in breach of its obligations in international law to respect state or diplomatic immunity. This paper develops this argument by considering three matters arising from our November 2024 paper. First, we assess what the Government has said since then about the ICC arrest warrant and about its obligations as a matter of UK law in relation to those warrants. We show that the Government has either misunderstood or misrepresented its legal obligations and seems intent on maintaining a state of uncertainty about the enforceability of the ICC arrest warrant in UK law, a position that does the Government no credit and cannot be reconciled with respect for the rule of law. Second, we consider again the immunity ratione personae of a serving Head of Government under customary international law. In our November paper, we took the view that State parties to the ICC Statute are still bound by the customary international law on immunities of senior State officials vis-à-vis non-State parties; most importantly for present purposes, they must observe the customary immunity ratione personae to which a serving Head of Government is entitled and which includes absolute immunity from arrest and from the exercise of foreign criminal jurisdiction. This view has received further support since we first outlined it. The UK would not be acting in breach of its international obligations in refusing to enforce the ICC arrest warrant against Prime Minister Netanyahu. Third, we examine the position of former Defence Minister Yoav Gallant. Being no longer in office, Mr Gallant is entitled only to immunity ratione materiae, which includes immunity from arrest and from the exercise of foreign criminal jurisdiction but only in respect of official acts. It would however be wrong to assume that the effect of the Pinochet ruling is that the immunity ratione materiae of former Minister Gallant would not extend to the crimes under the ICC Statute of which he is accused. We argue that this interpretation of the Pinochet ruling is incorrect. It thus follows that the Government has no authority under UK law to enforce the ICC arrest warrant against Yoav Gallant and any attempt to enforce the warrant,  including by transferring the warrant to an appropriate judicial officer to endorse, would place the UK in breach of its international obligations.     

London: Policy Exchange, 2025. 30p.