Mark Perry

Mark specialises in national security, public inquiries, technology and privacy.

He advises on all aspects of public inquiry work and is currently instructed as Solicitor to the Undercover Policing Inquiry.

Prior to joining TLT, Mark spent 14 years as national security lawyer within government, where he advised on legal issues concerning counter-terrorism, hostile state activity and the use of technology in national security operations. 

Mark is an expert on the use of covert and intrusive powers, including interception, equipment interference and bulk data. In government, Mark regularly advised cabinet ministers and engaged with senior judges regarding the lawfulness of surveillance and investigatory activities.

Mark has travelled widely in the US, Africa, Australia and the Middle East to address issues connected with intelligence co-operation and data sharing. He has extensive experience of the legal issues arising from cloud technology, artificial intelligence and quantum computing.

Mark has been instructed in many leading national security cases, including before the Supreme Court and European Court of Human Rights. They include:

• Wang Yam in the Supreme Court, concerning a murder committed by an alleged MI6 informant and whether domestic courts have jurisdiction to prevent sensitive material being put before the European Court of Human Rights.

• Amin v MI5 in the Court of Appeal concerning allegations of complicity in torture by British officials in Pakistan.

• Young v Home Office in the House of Lords concerning limitation periods in historic sexual abuse cases.

Jurisdiction: England and Wales

• Bank Mellat v HMT – $4.5 billion damages claim brought against HM Government following the imposition of financial restrictions on Bank Mellat which was accused of financing Iranian nuclear weapons development. Whilst instructed on this case, Mark led the largest closed disclosure exercise ever undertaken.

• As a national security lawyer in the Foreign and Commonwealth Office, advised ministers on the use of technology such as cloud, artificial intelligence, quantum computing and big data analytics in national security operations.

• Led legislative reforms to the Investigatory Powers Act 2018 which became law in the Investigatory Powers (Amendment) Act 2024.

• Solicitor to the Undercover Policing Inquiry.