Select Committee · Defence Committee

Defence in the Grey Zone

Status: Closed Opened: 18 Sep 2023 Closed: 14 Nov 2025 5 recommendations 9 conclusions 1 report

This inquiry was originally conducted during the 2019 Parliament and was interrupted by the 2024 general election. In November 2024 the re-established committee agreed to complete the inquiry. The grey zone can be defined as coercive activities that “…fall below perceived thresholds for military action and across areas of responsibility of different parts of the …

Reports

1 report
Title HC No. Published Items Response
5th Report - Defence in the Grey Zone HC 405 9 Jul 2025 14 Responded

Recommendations & Conclusions

14 items
1 Conclusion 5th Report - Defence in the Grey Zone Accepted

Defence capabilities against increasingly severe grey zone threats remain significantly limited.

Defence has a significant role in deterring and defending against grey zone threats, especially those of a more severe nature, including attacks on critical national infrastructure such as undersea data cables and energy pipelines. Despite an increase in the frequency and severity of these attacks, the armed forces have limited …

Government response. The government agrees and is taking specific actions, including strengthening home defence and resilience through the SDR, working with the Cabinet Office on infrastructure protection, exploring a Defence Readiness Bill and a new Reserve Force, and enhancing cyber capabilities via …
Ministry of Defence
2 Conclusion 5th Report - Defence in the Grey Zone Accepted

Expand current Defence capabilities to deter and effectively defend against grey zone threats.

The Ministry of Defence should consider how current capabilities can be further expanded to deter and defend against grey zone threats. (Recommendation, Paragraph 33)

Government response. The government agrees and is implementing specific measures outlined in the SDR, such as enhancing home defence, strengthening critical national infrastructure protection (including considering a Defence Readiness Bill and Reserve Force), and boosting cyber capabilities through Defence Digital, the National …
Ministry of Defence
3 Conclusion 5th Report - Defence in the Grey Zone Accepted

Increase effectiveness and number of Royal Navy vessels for seabed operations against grey zone threats.

The Ministry of Defence should consider the specific benefits of both expanding the number, and increasing the effectiveness of, Royal Fleet Auxiliary and Royal Navy vessels able to undertake seabed operations to better counter grey zone threats. (Recommendation, Paragraph 34) Extending defence against grey zone threats

Government response. The government agrees and is developing the 'Atlantic Bastion' concept for protecting critical undersea infrastructure, which includes a rapid growth in autonomous underwater sensors, drones, and a new class of autonomy command platforms, alongside existing capabilities like RFA PROTEUS and …
Ministry of Defence
4 Conclusion 5th Report - Defence in the Grey Zone Rejected

Joint Expeditionary Force requires credible deployable capabilities for effective grey zone threat combat.

The Joint Expeditionary Force’s freedom to operate independently should allow it to be more responsive and agile in combatting grey zone threats. But it can only do this if it possesses credible, deployable capabilities. Expanding membership of the JEF might also bring benefits. (Conclusion, Paragraph 44)

Government response. The government partially agreed, acknowledging the need for the JEF to have credible, deployable capabilities, but rejected the recommendation to expand JEF membership, instead highlighting the 'JEF+' mechanism for collaboration.
Ministry of Defence
5 Recommendation 5th Report - Defence in the Grey Zone Deferred

Enhance JEF’s deployable capability, including Royal Navy ships, to combat grey zone threats in the Arctic.

The Government should consider enhancing the JEF’s deployable capability to combat grey zone threats, such as protecting seabed infrastructure and permitting extended military operations in the High North/Arctic, for example by reinforcing the bows of Royal Navy ships, including the future Type 83 Destroyers. (Recommendation, Paragraph 45) 27

Government response. The government accepted the recommendation with caveats, stating that specific capability commitments, such as for the Type 83 Destroyer or future icebreaker capabilities, will be considered as part of the Defence Investment Plan due in autumn 2025.
Ministry of Defence
6 Recommendation 5th Report - Defence in the Grey Zone Accepted

Forward base additional military capabilities in the Baltic to deter grey zone threats and reassure allies.

The Government should consider the benefits of forward basing additional military capabilities for extended periods in the Baltic to enhance their deterrent value against adversaries, increase their responsiveness to grey zone threats, reassure allies, and protect the critical shipping lanes used to reinforce UK forces in Estonia. (Recommendation, Paragraph 46)

Government response. The government partially agrees but primarily highlights existing commitments and planned enhancements to the Forward Land Forces in Estonia and other NATO activities, rather than committing to a review or implementation of additional forward basing.
Ministry of Defence
7 Conclusion 5th Report - Defence in the Grey Zone Accepted

Defence must enhance protection of reliant digital networks and secure sufficient cybersecurity skills.

Digital networks are only as strong and resilient to cyberattack as their weakest links, and recent attacks indicate that the Ministry of Defence must do more to help protect all those networks it relies on to fulfil its mission— not just those which it directly controls. Defence also needs the …

Government response. The government agrees with the findings and is undertaking specific actions, including publishing new cyber security standards for suppliers, launching the Defence Cyber Protection Partnership, promoting NCSC's Active Cyber Defence, and implementing a 'Secure by Design' approach for all capabilities.
Ministry of Defence
8 Recommendation 5th Report - Defence in the Grey Zone Accepted

Review and report on Ministry of Defence plans to protect digital networks from cyberattack.

Within a year the Ministry of Defence should review and report back to us on its plans to better protect all the digital networks it relies on, allowing it to enhance the overall resilience of these networks to cyberattack. (Recommendation, Paragraph 61)

Government response. The government agrees to undertake the requested review of its plans to protect digital networks and report back to the Committee within a year.
Ministry of Defence
9 Recommendation 5th Report - Defence in the Grey Zone Accepted

Set out a clear plan for recruiting and retaining Ministry of Defence cyber and digital skills.

The Ministry of Defence should set out a clear plan and timetable for recruiting and retaining additional cyber and digital skills, such as adopting ideas from the Haythornthwaite Review and through direct partnerships with private IT companies or targeting suitably skilled individuals on a part or full-time basis. (Recommendation, Paragraph …

Government response. The government agrees on the importance of enhancing cyber and digital skills and outlines several initiatives, including a second tranche of the direct entry scheme in 2026, launching the ‘ZigZag Careers’ pilot, and developing a two-way secondment programme with industry. …
Ministry of Defence
10 Conclusion 5th Report - Defence in the Grey Zone Accepted

Homeland resilience will require more cross-Government planning and a dedicated Security Minister.

As the recent SDR sets out, homeland resilience will become a significant activity for the MOD in the coming years and will require more cross- Government planning and coordination. The MOD is unlikely to lead many of these work streams. However, even with limited resources, it can proactively make an …

Government response. The government highlights MOD's leading role in the Cabinet Office-led Home Defence Programme and the Resilience Action Plan (published July 2025). It also details actions to increase the visibility of the Armed Forces in society, including engaging with schools, expanding …
Ministry of Defence
11 Conclusion 5th Report - Defence in the Grey Zone Accepted

Increased armed forces visibility and engagement positively impacts military recruitment and preparedness.

This should also allow other departments, society and industry to be more aware of, and therefore more prepared for, the potential challenges ahead—relieving pressure on Defence to focus on its principal tasks during a national emergency or conflict. Greater visibility and engagement of the armed forces with society should also …

Government response. The government highlights MOD's leading role in the Cabinet Office-led Home Defence Programme and the Resilience Action Plan (published July 2025). It also details actions to increase the visibility of the Armed Forces in society, including engaging with schools, expanding …
Ministry of Defence
12 Recommendation 5th Report - Defence in the Grey Zone Rejected

Ensure a dedicated Homeland Security Minister coordinates national preparedness and resilience efforts.

The Government should ensure there is a dedicated Homeland Security Minister to coordinate across central, regional and local Government, industry and wider society to rapidly enhance the UK’s national preparedness and resilience. (Recommendation, Paragraph 80)

Government response. The government rejects the recommendation for a dedicated Homeland Security Minister, stating that the Chief Secretary to the Prime Minister and the Security Minister are already suitable and efficient leads for national resilience and security matters.
Ministry of Defence
13 Conclusion 5th Report - Defence in the Grey Zone Accepted

Adopt a 'leading from behind' approach to share MOD expertise with other departments.

The Ministry of Defence should proactively adopt a greater ‘leading from behind’ approach to sharing its leadership, organisational and wider expertise with other departments to bolster their intrinsic long-term resilience planning and preparedness. This should reduce their demands on the Ministry of Defence during any critical grey zone or conventional …

Government response. The government outlines MOD's leading role in the Cabinet Office-led Home Defence Programme and involvement in the Resilience Action Plan (published July 2025), which involves coordinating and engaging with various resilience actors. They also describe efforts to increase the visibility …
Ministry of Defence
14 Conclusion 5th Report - Defence in the Grey Zone Accepted

Proactively engage with wider society to build consensus on threats to the UK.

At societal level, the Ministry of Defence should draw on its understanding of the threats faced to make a greater impact by proactively engaging far more with wider society, both public and private—for example, critical national industries, schools and communities—to help generate a dialogue around those threats to the UK …

Government response. The government highlights MOD's active engagement with wider government, society, and industry, including its leading role in the Cabinet Office-led Home Defence Programme and the Resilience Action Plan (published July 2025). They also detail actions to increase the visibility of …
Ministry of Defence

Oral evidence sessions

5 sessions
Date Witnesses
25 Mar 2025 Air Commodore Matt Bressani OBE · Ministry of Defence, Luke Pollard MP · Ministry of Defence, Paul Wyatt · Ministry of Defence View ↗
21 Jan 2025 Dr Margriet Drent · Ministry of Defence (The Netherlands), Sir Alex Younger KCMG · Secret Intelligence Service (MI6) View ↗
14 May 2024 Jānis Garisons · Latvian Ministry of Defence View ↗
13 May 2024 James Appathurai · NATO View ↗
23 Apr 2024 Elisabeth Braw · Atlantic Council, Professor Andrew Mumford · University of Nottingham View ↗