This statement updates the House on the Investigatory Powers Commissioner’s investigation into how MI5 came to provide false evidence to the Courts on whether or not it had confirmed the status of ‘Agent X’ as a Covert Human Intelligence Source. This follows the then Home Secretary’s Written Ministerial Statement of 3 July 2025 and the Prime Minister’s Written Ministerial Statement of 16 September 2025.

Following the Direction provided by the Prime Minister in September 2025, Sir John Goldring, the Deputy Investigatory Powers Commissioner, has conducted a comprehensive investigation into how MI5 came to fall short of its high standards, ultimately misleading the High Court, the Investigatory Powers Tribunal, the Investigatory Powers Commissioner and associated Special Advocates. This investigation has now concluded, and Sir John Goldring’s report is complete. Its findings have been submitted to the Prime Minister and the Courts.

I would like to thank Sir Brian Leveson, Sir John Goldring and the wider team at IPCO for the hard work that they have undertaken over recent months. I am grateful for their willingness to complete this investigation at the behest of the Courts, which is outside the usual remit of IPCO’s work.

Sir John’s conclusions make stark reading. His report outlines a series of failings both individually and organisationally within MI5 that led to false evidence being included in its witness statements. The High Court and the Investigatory Powers Tribunal will now consider their next steps, and we will need to await the outcome of those judicial proceedings.

Nevertheless, I am taking decisive action to ensure that MI5 is held accountable for the failings identified in Sir John’s report and to strengthen the assurance mechanisms by which I hold the Director General to account for the actions of the Security Service. This includes a package of measures to enhance accountability, increase independent challenge, review key operational policies, and improve scrutiny of MI5’s litigation strategy and practice. Specifically, I will:

• Strengthen current structures where I hold the Director General of MI5 to account. This will continue to sit alongside extensive wider assurance and oversight across Government, Parliament and the Judiciary;

• Increase independent senior-level challenge and external leadership and accountability of MI5’s internal reform and improvement programmes;

• Enhance work across legal teams to better understand and scrutinise MI5’s approaches to litigation cases.

MI5 plays a critical role in keeping our country, and the public, safe. I am deeply grateful for the commitment and dedication of its staff. However, given the significance of its responsibilities, it is imperative that the Service maintains the highest standards of integrity, accountability and rigour, particularly in its engagement with the courts. This case demonstrates the damage to public, parliamentary and judicial confidence in our security services when MI5 gets it wrong.

Over the last twelve months, MI5 has undertaken a comprehensive programme of work to learn from and rectify the errors exposed by Sir John’s report, as well as previous independent reviews into this case, as has been recognised in the IPCO report. This work has made significant progress, but there is more to do, and MI5 must continue to learn and to hold itself fully to account. I believe the new measures this Government is taking to strengthen oversight will ensure it does.

A copy of the IPCO report will be placed in the Libraries of both Houses and will be available on IPCO’s website.