The British government’s military support for Israel and the weakening of constitutional controls on military interventions – UK Constitutional Law Association

From Arthur Balfour to Keir Starmer, British political leaders of all stripes have pledged, albeit of varying degrees, overall support for (then, a Jewish homeland and now) Israel. On the 26^th January 2024 however, in proceedings brought by South Africa, the International Court of Justice ruled that Israel’s recent military actions in Gaza were plausibly genocidal. Specifically, the ruling stated that ‘some of the rights claimed by South Africa and for which it is seeking protection are plausible’; those rights being ‘the rights of the Palestinians in the Gaza Strip to be protected from acts of genocide, attempted genocide, direct and public incitement to commit genocide, complicity in genocide and conspiracy to commit genocide’. The previous UK government’s response to the judgment was ‘that Israel’s actions in Gaza cannot be described as a genocide’. Similarly, the Labour Prime Minister has rejected such designation, while members of his government have deferred on the question about whether it is a genocide until the ICJ delivers its final judgment. Subsequent provisional measures were issued in March, noting the deteriorating humanitarian situation in Gaza where ‘famine is setting in’, and requiring Israel to cooperate with the UN and cease its blocking of aid and food; and in May, noting further deterioration, in particular Israel’s attacks on the ‘safe refuge’ in Rafah, where hundreds of thousands of Gazans had been displaced, and demanding Israel halt its intended military offensive in that area.

While a final judgment on whether Israel is carrying out a genocide in Gaza will take years, (its bombing and blocking of aid into Gaza continues, while the Israeli PM says it is ‘seizing territory’); and though the three provisional orders of the ICJ are only binding on the parties to the claim, the UK also has obligations under international law to prevent and not be complicit in genocide (Articles 1 and 3, Convention on the Prevention and Punishment of the Crime of Genocide; for an explanation of the difference between ‘prevention’ and ‘complicity’ see also Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v. Serbia and Montenegro) [2007] ICJ para. 432); as well as under domestic law (Part 5, International Criminal Court Act 2001) to not commit or, as s.52 states, ‘engage in conduct ancillary’ to genocide, the meaning of which  includes, ‘aiding, abetting, counselling or procuring the commission of an offence’ of genocide or ‘assisting an offender or concealing the commission of an offence’, as stated in s.62.

The UK government currently does not recognise the state of Palestine and abstained on the UN General Assembly resolution granting Palestine non-observer status. Conversely, it has provided significant political, trade and diplomatic support for Israel. Over the past 18 months, it has continued to re-affirm what it understands as Israel’s right to self-defence. In a recent PMQs, Keir Starmer spoke out against a ruling of the Upper Tribunal which allowed a family from Gaza to relocate to the UK during the war, originally using the form designed for the Ukraine Family Scheme. When On 21^st November 2024, the International Criminal Court issued arrest warrants for Israel’s Prime Minister and (now former) Foreign minister, the previous Conservative-led government initially questioned the jurisdiction of the ICC to adjudicate on the matter (though the current government has changed course and said they would respect such warrants). On the 2^nd September 2024, the UK government suspended some of itsarms export licenses to Israel but, crucially, maintained its supply of F-35 parts which have been central to Israel’s aerial assault on the Gaza Strip (the exemption of F-35 parts is currently the subject of judicial review proceedings being brought by Al Haq and Global Legal Action Network, in which a hearing is set to take place in May 2025).

To what extent then, does the UK constitution regulate the UK government’s military support of Israel’s war on Gaza and its potential ‘conduct ancillary’ to genocide? Though all of the aforesaid are of interest to us as public lawyers, in this blog post, I will examine a particular element of the UK government’s support for Israel: a) providing its military assets to target Israel’s regional adversaries and b) the intelligence, surveillance and reconnaissance (ISR) missions carried out by the UK government on Israel’s behalf. These two threads, I will intimate, demonstrate a weakening of constitutional controls around military deployments, through ‘mission creep’ (the gradual expansion of a military or policy objective beyond its original scope, often without explicit authorization) and ‘redeployments’ (transferring military forces, personnel, or resources from one operational area to another, often in response to strategic, logistical, or political considerations). While this blog post does not go into detail as to why this weakening is happening, I suggest that this is part of a trend of growing executive power.

Law and politics of military deployments

As is well understood, ‘it is the right of the Crown in the interests of the State to decide in peace and war all matters relating to the disposition and armament of the military, naval and air forces’ (Chandler v DPP [1964] A.C. 763, [1962]; see also China Navigation Company, Limited v Attorney-General [1932] 2 K.B. 197). Such prerogative right, though it has been previously challenged, remains non-justiciable for the purposes of common law review (Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374; Campaign for Nuclear Disarmament case [2003] 3 LRC 335; Secretary of State for the Home Department v Rehman [2003] 1 AC 153; R (Marchiori) v Environment Agency [2002] EuLR 225). As Lord Hoffmann pithily put it, ‘the disposition of the armed forces has always been regarded as a discretionary power of the Crown into the exercise of which the courts will not inquire’ (R v Jones and others; Ayliffe and others v Director of Public Prosecutions; Swain v Director of Public Prosecutions [2006] 2 All ER 741).

However, as has been noted, a convention emerged in 2003, when under significant anti-war pressure, the Blair administration was forced to consult Parliament in a non-binding vote over military intervention in Iraq. This convention was formalized with its reception into the Cabinet Manual and observed on four occasions between 2011 and 2015 over interventions of varying degrees in Libya, Iraq and Syria. Perhaps most significant in affirming the normative force of the convention was David Cameron’s decision in 2013 to honour a parliamentary majority against his preference to launch airstrikes in Syria.

However, there has since been an abrupt softening of the convention. In 2018, Theresa May launched airstrikes in Syria without parliamentary consent (earlier statements reflecting a willingness to do so had been made by Boris Johnson,  then Foreign Secretary, in 2017). In 2019, the PACAC published a report Authorizing the Use of Military Force which recommended, among other things, that the Cabinet Manual be updated to detail the convention with ‘a clearer exposition of the exceptions’, require the government to seek retroactive approval if an exception is engaged, provide as much information in advance as possible to the House of Commons when a deployment decision is being discussed and approved, and to set out the convention in a House of Commons resolution (which it provided a draft for). The then Government (now under Johnson’s leadership) responded to the report and though it reaffirmed its commitment to the convention, it rejected many of the recommendations, including the draft resolution, arguing that formalisation would limit its ability and expediency to act. Between January and May 2024, under the Conservative government, the UK participated in the US-led Operation prosperity Guardian targeting Ansar Allah (aka Houthis) in Yemen who had disrupted commercial shipping lanes in the Red Sea which it understood as connected to Israel and its war on Gaza . While there were some discussions in Parliament regarding some of the airstrikes against the Houthis, there was no vote on such action. Indeed, since May was Prime Minister, the convention seems to have become subject to all manner of new caveats. Despite promises from Starmer during his leadership campaign to introduce a Prevention of Military Intervention Act, no such action has been taken by his administration.

Military deployments as redeployments

The UK government has sought to use its military assets to assist Israel against its regional adversaries (indeed, as the previous paragraph demonstrates, over the past two decades, the UK has either directly or indirectly targeted most of Israel’s antagonists including Syria, Ansar Allah and The Popular Mobilization Forces in Iraq, otherwise forming part of Iran’s informal Axis of Resistance). On April 13^th 2024, the UK intercepted Iranian drones headed for Israel. The Islamic Republic of Iran had launched these missiles in retaliation for the bombing of their consulate in Damascus which had killed several of their generals, and which they accused Israel of committing (Israel has a track record of striking Iranian targets, as well as bombing targets in Damascus). Interestingly, the UK government redeployed military assets already in the region (as part of military campaign Operation Shader, launched  against Daesh targets in Iraq in 2014 and Syria in 2015). While these initial airstrikes against Daesh were discussed and approved by Parliament in September 2014 and December 2015 respectively (and thus following the convention to consult Parliament), there was no separate parliamentary discussion or vote to redeploy these military assets against Iran. On the 15^th April 2025, the PM was asked by the Lib Dem MP Richard Foord why there had been no parliamentary discussion (albeit post factum, as was the case in Libya in 2011), in what Foord presumably thought was a distinct military deployment. Starmer’s response was that he had to act quickly to an ‘immediate and dangerous threat’. In October 2024, following Israel’s killing of Hamas’ political leader, Ismail Haniyeh, the former General Secretary of Hezbollah, Sayyed Hassan Nasrallah and senior IRGC commander, Abbas Nilforoushan, Iran launched missile strikes against Israel. As this House of Commons briefing states however, though UK RAF Typhoon jets were deployed, they did not actually intercept any missiles. Israel responded with several strikes on Iranian soil and while Starmer repeated that Israel had a right to defend itself, he urged Iran not to respond.

Redeployments of military assets are not unusual, of course. One’s intuition might be that all military forces are literally deployed from the UK mainland, but the UK maintains military bases and installations (like aircraft carriers) across the world. After the invasion of Iraq, many British forces were shifted from Afghanistan to Iraq and later redeployed back to Afghanistan as the focus on Iraq receded. In 2011, UK aircraft were moved from Afghanistan operations to enforce a no-fly zone over Libya. However, these redeployments both involved parliamentary votes (before and after the deployment, respectively). Redeployment then is a useful form of statecraft as it allows military assets to remain supple. However, it appears that in recent strikes, redeployment has become a way in which to circumvent already weak controls on the PM’s prerogative power, not necessarily by creating another exception or ‘caveat’, but by extending the scope of already deployed military assets. In the Parliamentary discussion on military intervention against Daesh, there was no discussion or vote on whether these assets would be used against Iran (indeed, the attacks against Daesh involved a rare convergence of interests between the UK, US and Iran). In effect, this was an example of an entirely separate deployment, but one which, under the discourse of redeployment, was able to avoid parliamentary discussion and a vote. It seems easy, therefore, to imagine how ‘redeployments’ could be used in the future to avoid a vote in the Chamber.    

ISR and mission creep

On the 2^nd December 2023, three government departments published a press release stating that the UK ‘will conduct surveillance flights over the Eastern Mediterranean, including operating in air space over Israel and Gaza’. It made clear that the ‘surveillance aircraft will be unarmed, do not have a combat role, and will be tasked solely to locate hostages’. A few days later, Grant Shapps was asked about these flights and stated that ‘we would provide only defensive matériel, or matériel that might help with the recovery of hostages.’  Despite further questions in Parliament, (see here, and more recently here) the Government has maintained that is it only using these reconnaissance flights for rescue of Israeli captives. A recent investigation carried out by DeclassifiedUKand Action on Armed Violence found that the UK had launched over 500 flights from the 3^rd December 2023 from its overseas territory, the Sovereign Base Areas (on the southern coast of Cyprus), which houses an RAF military base. However, in October 2023, the Israeli newspaper Ha’aretz published a report of US and UK aircrafts carrying ‘equipment, arms and forces’. Therefore, many remain sceptical about the government’s assurances (see here and here). Indeed, on April 1^st 2025, The Times reported that the MOD had refused to release video footage from a British spy plane that had been flying over Gaza on the day Israel killed several aid workers from the World Central Kitchen.

There are two potential problems here. The first, a skeptic might argue, is that in the absence of any transparency by the MOD, it could simply be that the UK government is concealing that it is in fact providing combat assistance for Israel. One would expect therefore, that this would engage the convention and require a parliamentary vote. The second, and a more charitable position in taking the Government’s word at face value, is that the UK’s reconnaissance flights could easily shift into direct combat operations, or mission creep. Indeed, one might also argue whether there is a qualitative difference between gathering intelligence for the rescue of captives, and the use of this intelligence for lethal targeting (which, as the World Central Kitchen episode shows, has resulted in the targeting of civilians). Mission creep has occurred in other moments of the UK’s previous deployments. In 2013, when a small contingent of British troops were deployed to Mali in a non-combat, logistical and then surveillance capacity, they were drawn into combat operations, for which the requisite parliamentary vote did not take place. Again, being charitable, it is reasonable to envisage that initial deployments for non-combat operations could shift, whether through the will of senior military officials, or through circumstances, into combat operations. Ultimately, however, either eventuality could, as with Mali, preclude any parliamentary involvement.

In other words, redeployment of military assets and mission creep potentially work to further dilute already comparatively weak controls on the PM’s prerogative to deploy troops and provide military support for its allies. While the PM’s exercise of the war powers prerogative will be informed by the Government’s own legal advisors, and advice from senior military and intelligence officials, in the absence of any parliamentary discussion, one might argue that legal obligations (under international and domestic law) that could shape such a discussion, are being trumped by political expediency. Indeed, such assistance might, when the ICJ decides, ultimately be seen as conduct, to quote the UK statute, ancillary to genocide. While recognising that military deployments cannot be judicially reviewed, what this all appears to demonstrate more broadly is a shift from what our field has understood as legal constitutionalism to a nascent decisionism which is shredding modest political and legal controls on the exercise of executive power.  

The author would like to thank the editors of the blog for their comments.

Tanzil Chowdhury is a Senior Lecturer in Public Law at Queen Mary University of London