National security interventions have largely been confined to defense-related transactions

Changes to the national security landscape that were originally thought to have been published in 2019 have not yet been published. It is anticipated that changes will not be implemented until sometime in 2020.

Since mid-2018, there have been a number of important changes (actual and proposed) to legislation permitting intervention by the UK government in transactions that may raise national security concerns. Unlike many other jurisdictions, acquisitions in the UK in potentially sensitive industries do not, as a matter of course, require parties to seek approval from a regulator or the government.

Following a government consultation designed to "strengthen powers for scrutinizing the national security implications of particular types of investment," the notification regime remains voluntary. However, a number of changes have been implemented to strengthen the government's powers and allow for intervention in a wider range of cases.


The government adopted some changes in June 2018, and is also proposing more wide-reaching changes that will require a new Act of Parliament. The changes introduced in June 2018 were designed to fill a gap and cover those cases with the greatest potential to raise national security concerns but which were not caught by existing legislation.

These short-term changes amended the Enterprise Act 2002 to reduce the thresholds at which interventions could be made in cases involving a target active in one of three areas: the development or production of military or dual-use goods; the design and maintenance of computing hardware; and the development or production of quantum technology.

The government can now intervene in an acquisition in any of these areas if the annual UK turnover of the target is £1 million or more (reduced from £70 million, which remains the threshold for all other cases), or if the target alone accounts for 25 percent or more of purchases or sales of any goods or services in the UK. Previously, the parties had to overlap such that there was an increment leading to a combined share of supply of 25 percent or more. This requirement no longer exists for cases in the three identified sectors, and a deal can be caught even if there is no overlap with the purchaser.

The government anticipates between five and 29 additional cases per year will be caught by the amendments that came into force in June 2018.


The government's long-term objective is to more comprehensively reform its powers of scrutiny over investments that may pose a risk to national security. The intention is to implement this regime with a new piece of primary legislation.

Under the proposed changes, notification will remain voluntary, but parties will be encouraged to notify their transaction. As with the UK's general merger regime, transactions that are not notified may be subsequently investigated and remedies imposed if found to be problematic. The government expects approximately 200 notifications per year under the new national security regime and that approximately half of these will progress to a full assessment. Of those, the government estimates that 50 will result in a remedy of some sort, which could vary from implementing some ringfencing (e.g., of individuals and/or information) to outright prohibition.

Where parties choose not to notify, the government may still decide to "call in" transactions that result in a "trigger event." It is proposed that these trigger events will include the acquisition of more than 25 percent of an entity's shares or votes, significant influence or control over an entity, or further acquisitions of significant influence or control over an entity beyond these thresholds. Acquisitions of assets will also be covered, which is not always the case under the existing rules. The timescale for post-closing intervention in national security cases will be increased to six months after the details of the transaction are in the public domain (the current time limit is four months).

The government has indicated that it will consider three factors when determining whether a trigger event could lead to a national security risk: "target risk," whereby the entity or asset in question could be used to undermine national security (i.e., where the nature of the target's business could pose a potential risk); "trigger event risk," whereby the acquisition itself gives someone the means to undermine national security (e.g., by affording greater opportunity for disruptive actions or espionage); and "acquirer risk," where the acquirer itself has the potential to use its control over the target to undermine national security (e.g., where acquisitions are carried out by entities controlled by hostile states or other hostile parties).

The new legislation will provide that all national security considerations be assessed by the government. Therefore, the existing role of the Competition & Markets Authority (CMA)—the UK's main antitrust agency—to investigate and report to the government when an intervention is made will be removed. The proposed legislation will also introduce civil and criminal sanctions to deal with noncompliance with any remedies that might ultimately be imposed.

The government was originally expected to publish draft legislation in 2019, following its assessment of comments received as part of the current consultation process. However, due to other government business (principally related to Brexit) no draft has yet been published. As a degree of uncertainty still surrounds details of the proposed new regime and the fact that any new legislation is unlikely to take effect until 2020 at the earliest, the remainder of this article focuses on the existing law.


As there are currently no specific requirements relating to deals that may raise potential national security issues, strictly speaking no person needs to file an application. Rather, if the UK government considers that a deal raises national security issues, the Secretary of State (SoS) may issue an "intervention notice."

The procedures for the SoS to issue an intervention notice, and—if considered appropriate—ultimately block a deal, are set out in the Enterprise Act. If an intervention notice is served, then the acquirer (and others as appropriate) will be required to provide information.


The Enterprise Act currently allows the SoS to intervene when specified public interest considerations arise. In addition to national security, the other specified public interest considerations relate to media plurality, quality and standards, and the stability of the UK's financial system. These powers have been bolstered by the June 2018 amendments mentioned above if the target is active in military or dualuse goods, computing hardware or quantum technologies.

Prior to the June 2018 amendments, there was no guidance as to what industries were relevant to national security, although in all but one case national security intervention notices involved defense considerations. The lowering of thresholds for transactions involving targets active in computing hardware and quantum technology in June 2018 indicates that there is potential going forward for a greater number of non-defense-related transactions to be scrutinized on national security grounds.

The first government intervention under the new thresholds was in the aerospace sector, with a target active in the manufacture of dual-use goods. That case—the proposed acquisition of Northern Aerospace Limited by Gardner Aerospace Holdings Limited, a Chinese company—was ultimately cleared by the government (although the intervention caused the deal to be abandoned).

In cases to date, the Ministry of Defence on several occasions raised concerns about the maintenance of strategic UK capabilities and the protection of classified information, including when the acquirers have been from the US or other NATO allies. In these cases, the deals have been approved following undertakings provided by the acquirer to address the concerns, often involving the ring-fencing of sensitive information.


When an intervention notice on national security grounds is issued, the CMA must investigate and report to the SoS—but, as noted above, the legislative proposal is to remove the CMA from all national security reviews. Under the current system, the CMA will consult on the national security issues and its report will summarize any representations received on the matters specified in the SoS's intervention notice and, where relevant, will also deal with any competition issues.

The SoS will consider the CMA's report and decide whether the transaction should be subject to a more in-depth "Phase 2" review by the CMA, or whether to accept any undertakings the acquirer may have offered to address public interest concerns, or indeed—which has never happened to date—whether the public interest concerns are not warranted or do not require any remedial action.

If there is an in-depth review by the CMA, it is required to report whether the transaction operates or may be expected to operate against the public interest, and make recommendations as to the action the SoS or others should take to remedy any adverse effects. The SoS will make the final decision on the public interest issues and any remedial steps to address the public interest issues.


During 2019, two cases have been reviewed by the CMA on instruction by the SoS in light of potential national security concerns.

In September 2019, the SoS issued an intervention notice in connection with Advent International Corporation's proposed acquisition of Cobham Plc. Cobham is known for pioneering the technology that allows for the mid-air refueling of planes, and also for manufacturing electronic warfare systems and communication systems for military vehicles.

In July 2019, Advent International offered to buy Cobham for £4 billion, a deal approved by its shareholders. However, various concerns were raised (including by Cobham's founding family) about the company's future and its connections with UK defense.

Following the intervention notice on grounds of national security concerns, the CMA investigated the transaction, considering in particular national security implications, and submitted a report to the SoS at the end of October 2019. The report includes a summary of any representations that the CMA receives that relate to the public interest consideration, national security, and which generally may be relevant to the SoS's decision. No decision has yet been made. The SoS has also received comments from the Secretary of State for Defence about the national security implications of the merger, and will decide whether the transaction operates, or may be expected to operate, against the public interest and, if so, whether it should be referred to a more in-depth Phase 2 review. However, at the time of this writing, the government has announced its intention to accept undertakings submitted by the parties, and it is expected that these will be approved. The proposed undertakings involve upholding existing security arrangements around sensitive information, requiring Cobham's new owners to honor existing contracts and requiring Cobham's new owners to notify the Ministry of Defence of any plans to sell the whole, or parts, of Cobham's business.

Although Cobham is active in defense-related areas, the fact that the SoS reviewed a case concerning a US acquirer suggests a potentially tougher approach being taken to FDI in the UK—even though it is expected that the deal will ultimately be cleared with some undertakings.

In the second case, in July 2019, the SoS also intervened in a defense and aerospace deal between Connect Bidco Ltd. and Inmarsat plc. Inmarsat operates satellites that manage critical government communications for the UK (and other countries), particularly in emergency services, naval operations and border control.

In this case, the CMA announced the launch of its merger inquiry and brought it to the attention of the SoS, as the CMA thought the transaction may also raise public interest considerations.

The SoS issued an intervention notice on grounds of national security. The CMA submitted its report to the SoS in mid-September 2019 and concluded that the transaction did not raise any competition concerns. As far as national security was concerned, the parties offered undertakings to provide assurances that sensitive information will be protected and enhanced security controls will be in place to ensure the continued supply of key services used by the Ministry of Defence. The measures include a high standard of physical security in relation to company processes and premises, system security in relation to IT systems, and personnel security in relation to employees and management. Connect Bidco and Inmarsat also undertake to continue the provision of certain capabilities and to maintain a UK-registered company to ensure that services remain in the UK's jurisdiction. The Ministry of Defence will also be allowed to audit compliance with security measures.

In October 2019, the SoS accepted the parties' undertakings as appropriate to mitigate the national security risks.


The specific focus in the recent reforms on military and dual-use technology, quantum technology and computing hardware reflects the fact that national security risks are increasingly likely to arise in the technological and cyber spheres. As general concerns about cybersecurity and control of critical infrastructure networks become more commonplace, it would not be surprising to see more SoS interventions on national security grounds.


Potential issues should be considered as early in the planning process as possible, and increasingly in any case—not just defense-related deals—that might be considered to touch on national security. State-owned acquirers, or those with material links to (or financing by) stateowned enterprises, should be particularly well prepared, and consider what undertakings they might be prepared to give, if concerns are raised.

To date, such undertakings have tended to relate to ensuring the protection of classified information and ensuring UK capabilities. Early engagement with the relevant government departments would also be sensible, especially if an auction process is likely, because the target will want to ensure that the acquirer is able to complete any proposed deal. The collapse of the Gardner/ Northern deal may have been due, in part, to inadequate planning and preparation on the potential national security issues.


Under the current regime, the CMA typically reports to the SoS within four to six weeks of the intervention notice, with the SoS's decision following shortly thereafter. If the SoS decides the CMA should conduct a Phase 2 investigation, it will take up to a further 24 weeks (followed by the time for the SoS to reach a final decision).


  • The wide-ranging changes to the national security landscape that were originally thought to have been published in 2019 have not yet been published. It is anticipated that changes will not be implemented until sometime in 2020. The revised regime will remain voluntary, meaning that there will be no obligation to notify deals that may affect national security. However, nonnotified deals will be susceptible to review for up to six months after details become public
  • During 2019, two cases have been reviewed by the CMA on instruction by the SoS in light of potential national security concerns. One has been approved subject to the parties' undertakings to address the SoS's national interest concerns, and the other is still under review, but it is thought that it, too, will be cleared with relevant undertakings
  • While there is arguably now a tougher approach to transactions raising national security concerns as these deals are subject to more scrutiny, it is anticipated that the majority of these will be approved with some undertakings. To date, there have been no prohibitions


  • No deal has been blocked by the SoS on national security grounds
  • All national security cases to date have resulted in behavioral remedies (e.g., ring-fencing information and ensuring strict controls are in place) in lieu of a detailed Phase 2 investigation. No divestments have been required
  • Intervention on national security grounds is no longer limited only to defense related transactions
  • The radical changes proposed by the government to the rules for reviewing deals potentially affecting national security are likely to have a material impact on M&A in the future