This article briefly considers how private prosecutions might be used to prosecute international criminal offences, an issue highlighted by relatively recent cases including R (on the application of General Abdulwaheed Shannan Al Rabbat) v. Westminster Magistrates’ Court. This case involved an attempt to bring a private prosecution against former senior politicians for the international crime of aggression. Whilst the crime of aggression was found not to be an offence under the laws of England and Wales, there are a number of international crimes that are. The Al Rabbat case highlights the potential role that private prosecutions can play in cases involving international crimes, which this article will explore.
The crime of aggression: international jurisdiction
The discourse surrounding the prosecution of the crime of aggression has developed since the activation by the International Criminal Court (“ICC”) of its jurisdiction over the fourth ‘core crime’ of the Rome Statute (the UN treaty creating the ICC). From 17 July 2018, the ICC has been able to hold leaders individually criminally responsible for waging aggressive war. The Court’s jurisdiction is restricted to those States that have ratified the aggression amendment, presently 36 of the 123 States Parties to the Rome Statute, in which the United Kingdom does not feature. Further conditions to the exercise of the court’s jurisdiction apply.
The crime of aggression is defined as “the planning, preparation, initiation or execution, by a person in a position effectively to exercise control over or to direct the political or military action of a State, of an act of aggression which, by its character, gravity and scale, constitutes a manifest violation of the Charter of the United Nations.” 
In the case of R (on the application of General Abdulwaheed Shannan Al Rabbat) v. Westminster Magistrates’ Court , the Divisional Court refused permission for judicial review of the refusal of Westminster Magistrates’ Court to issue a summons for a private prosecution against Tony Blair, Jack Straw and Lord Goldsmith for the international crime of aggression concerning the invasion of Iraq in 2003. The private prosecutor asserted that the crime of aggression existed under the law of England and Wales. The Attorney General, intervening, contended that permission should be refused, as the crime of aggression was unknown to the law of England and Wales.
In R v Jones, Milling & Others , similarly within the context of the invasion of Iraq, the House of Lords unanimously ruled that while the crime of aggression exists under customary international law, there is no such offence under the law of England and Wales. The claimant in Al Rabbat contended that the Divisional Court should certify a general point of law of public importance as to the correctness of the decision in Jones. The Divisional Court was bound by this decision and concluded that there was no prospect of the Supreme Court departing from its earlier decision if permission were granted.
Prosecution of international criminal offences within the United Kingdom
The law of England and Wales recognises a number of crimes over which there exists universal jurisdiction. That is to say, prosecutions can be brought irrespective of the offender’s nationality, where the offending took place or whether there is any connection with England and Wales. A private prosecution can potentially be brought in such cases. These offences include:
There is jurisdiction in the UK over the offence of torture, contrary to s.134 Criminal Justice Act 1988 (“CJA 1988”) irrespective of nationality, where the offence was committed or whether the defendant is resident in the UK. This provision was used in the case of Zardad  EWCA Crim 1640 to successfully prosecute an Afghan warlord for torture committed in Afghanistan. The recent prosecution of a Nepalese General for offences of torture committed in Nepal is another example.
To achieve a prosecution for torture it must be proved that:
- A public official or person acting in an official capacity intentionally inflicted severe pain or suffering on another in the performance or purported performance of his official duties, section 134(1) CJA 1988; or
- A person intentionally inflicted severe pain or suffering on another at the instigation or with the consent or acquiescence of a public official or a person acting in an official capacity, section 134(2) CJA 1988.
The Taking of Hostages Act 1982 (“THA 1982”) provides that this offence may be committed by a person irrespective of his nationality and irrespective of where the offence occurred. This provision was also used in the Zardad case successfully to prosecute the defendant for hostage-taking.
A person is guilty of this offence if he detains any other person (“the hostage”), and in order to compel a State, international governmental organisation or person to do or abstain from doing any act, threatens to kill, injure or continue to detain the hostage, section 2(1) THA 1982.
The Geneva Conventions Act 1957 creates offences concerning grave breaches of the Geneva Conventions committed in international armed conflicts to which the four conventions and the additional protocol apply. Universal jurisdiction under section 1 provides:
Any person, whatever his nationality, who, whether in or outside the United Kingdom, commits, or aids, abets or procures the commission by any other person of a grave breach of any of the scheduled conventions shall be guilty of an offence.
Grave breaches are those involving any of the following acts, if committed against persons or property protected by the Convention: wilful killing, torture or inhuman treatment, including biological experiments, wilfully causing great suffering or serious injury to body or health, and extensive destruction and appropriation of property, not justified by military necessity and carried out unlawfully and wantonly. 
The War Crimes Act 1991 (“WCA 1991”) allows proceedings for murder, manslaughter or culpable homicide to be brought against a person in the United Kingdom (providing he was on 8th March 1990, or has subsequently become, a British citizen or resident in the UK), irrespective of his nationality at the time of the alleged offence if that offence:
- was committed between 1st September 1939 and 5th June 1945 in a place which at the time was part of Germany or under German occupation; and
- constituted a violation of the laws and customs of war (section 1 WCA 1991).
The core international crimes within the jurisdiction of the International Criminal Court namely, war crimes, crimes against humanity and genocide were domestically implemented by the International Criminal Court Act 2001. Whilst there is universal jurisdiction for offences committed under section 1, a prosecution can only be brought against a UK national, resident or person subject to UK service jurisdiction. Temporary visitors to the UK are thus excluded under these provisions.
Consent to prosecute
Allegations involving international crimes invariably require the consent of the Attorney General to bring by way of a private prosecution. Generally speaking, the consent of the Attorney General is required in relation to offences/allegations that raise issues of public policy, national security or relations with other States. International criminal offences and their prosecution are highly likely to give rise to political issues and matters of international comity.
Prior to 2012, a private prosecutor could apply for an arrest warrant, prior to such consent having been sought. However, section 153 of the Police Reform and Social Responsibility Act 2011 removed this ability following such warrants being sought in relation to several high profile individuals which were perceived to be solely for political/campaigning purposes, including Henry Kissinger, Bo Xilai, Ehud Barak and others. Nonetheless, it remains the position that consent can be sought from the Attorney General in appropriate cases.
In Jones it was noted by Lord Bingham that it would be anomalous if there were jurisdiction over the crime of aggression, even though it was not included in the International Criminal Court Act 2001, as it would not be subject to the same constraints applicable to offences that were, including: the need for consent to prosecute from the Attorney General, maximum penalties and the liability of secondary parties. 
The process of seeking consent from the Attorney General involves submission of the evidence gathered by the private prosecutor and draft charges along with a list of the public interest factors which tend in favour of a prosecution and those which tend against. The Attorney General’s consent should be obtained at the earliest reasonable opportunity.
If consent is sought from the Attorney General to pursue international criminal offences by way of a private prosecution and such consent is granted, it could result in the prosecution being taken over by the state. In cases where consent is sought from the Director of Public Prosecutions for a private prosecution and such consent is given, CPS policy provides: “if the proposed prosecution passes the Full Code Test, the CPS will then take over the prosecution.” Given the sensitive issues likely to be involved in offences of this nature and the policy reasons behind the requirement for the Attorney General’s consent, it seems likely that where consent is granted, the prosecution will be taken over, although this is not a foregone conclusion.
There is a potential role private prosecutions can play in holding those responsible for the commission of gross human rights violations and international crimes to account. In cases where there has initially been a reluctance or inability on the part of the state to investigate or prosecute, seeking consent to pursue a private prosecution might in appropriate cases provide a useful route to obtaining justice. Whilst the crime of aggression is not yet an offence under the law of England and Wales, there remain other international crimes over which the English Criminal Courts can assert jurisdiction.