The leaking of State secrets is a recurring theme in spy fiction – and in criminal law. Some of the most compelling spy fiction, and the most interesting criminal prosecutions, have emerged when the agent seeks to defend his actions and to justify why he betrayed his country. The reasons range from a warped allegiance to the enemy (such as Cold War double agent Kim Philby) to a desire to expose misconduct within his own ranks (such as former CIA agent turned anti-snooping activist Edward Snowden).

Prosecutions of agents for leaking State secrets should be seen in the context of the wider legal debate about the balance to be struck between national security and transparency. This debate is an old one, but it has reared its head repeatedly in recent months. Earlier this week, Martin Chamberlain QC, a leading special advocate in terrorism and national security cases, proposed that a cadre of expert judges who are not “overawed” by the intelligence services should help safeguard against potential abuses in mass surveillance.

This recommendation follows the revelations in the secret trial of Erol Incedal for terrorism offences. Earlier this month, it was publicly revealed for the first time that MI5 had made representations to the Director of Public Prosecutions that this trial should proceed in complete secrecy (going beyond the measures taken in the murder trial R v Wang Yam for example). The reasons for such secrecy cannot be disclosed due to the reporting restrictions in place. The Guardian is appealing against the restrictions. Hearing the appeal, the Lord Chief Justice was prompted to comment on the importance of open justice. He made it clear that it was essential that MI5 and the SIS are held to be subject to the rule of law: “One of the issues [in the appeal] is the public having confidence in the way the security services work. The accountability of the security services is another issue that arises.”

Looking ahead to next month, the Supreme Court will hear the claim of Abdel Hakim Belhaj, who alleges that the UK intelligence and security services were complicit in his rendition to and torture in Libya. The Court of Appeal rejected the Government’s argument that the case should not be heard, holding that MI5 and the SIS are “not entitled […] to any immunity before the courts in this jurisdiction […] there is a compelling public interest in the investigation by the English courts of these very grave allegations.”

These recent developments are evidence of a resistance to the looming spectre of the UK’s secrecy laws, and the assumption that national security considerations should automatically take precedence over public scrutiny by the judiciary of the intelligence services.

Coming in from the cold

When it comes to prosecuting agents who come in from the cold and leak State secrets, the balance between national security and transparency was affected most profoundly by the introduction of the Official Secrets Act 1989, which removed the ‘public interest’ defence in respect of the following offence:

S1 (1) A person who is or has been –

1) A member of the security and intelligence services, or

2) A person notified that he is subject to the provisions of this section,

is guilty of an offence if without lawful authority he discloses any information, document or other article relating to security or intelligence which is or has been in his possession by virtue of his position as a member of any of those services in the course of his work while the notification is in or was in force.

Considerations such as the lack of damage caused by the disclosure, or the prior publication of the disclosure, offer no defence. Nor is any distinction made between a harmful and harmless disclosure. This change in law followed the acquittal of Clive Ponting, a Ministry of Defence employee who was charged with leaking an internal MoD document to a Member of Parliament. Ponting was prosecuted under the old Official Secrets Act 1911. His defence was that his disclosure was in the public interest and, despite the judge indicating that the jury should convict him, he was acquitted. The government’s response to his acquittal was to re-draft the legislation to remove the public interest defence. The balance of the criminal law was thus shifted dramatically in favour of national security considerations, with no apparent scope for exploring whether the agent could defend himself by seeking to justify his leaks.

Tinker, Tailor, Soldier, Shayler

The impact of the removal of the public interest defence was illustrated vividly by the prosecution of David Shayler under sections 1 and 4 of the 1989 Act. He was an MI5 officer, prosecuted and convicted of passing secret documents to the Mail on Sunday. His case raised a number of important issues. Firstly, whether his Article 10 rights had been breached by his inability to argue a public interest defence. The House of Lords held that whilst there was a prima facie restriction upon his freedom of expression, the fact that he could have made a lawful disclosure, by following the correct procedure and seeking authority in advance, meant that this restriction was proportionate. Consequently, any attempt to refashion the repealed public interest defence as a human rights argument could not hold water. Secondly, whether a defence of necessity of circumstances or duress could be raised in respect of these offences. The court held that such defences were not open to Shayler; whilst they could not be ruled out per se, in the circumstances of the case they were not made out. Shayler had not been compelled to make the disclosure in the normal terms of those defences.

On its face, therefore, bringing a prosecution under the Official Secrets Act 1989 for an unauthorised disclosure under section 1 should be relatively straightforward. One might question whether the defence, deprived of any public interest arguments, have any real scope for contesting the allegations.

For your eyes only

Whilst the current law leans in favour of the prosecutor, problems can arise when the law is applied in practice. When the CPS considers the two stage charging test, the evidential sufficiency stage is likely to pose no great hurdle, but what considerations need to be given to whether a prosecution is in the public interest? Former MI6 agent Richard Tomlinson faced prosecution twice; first for disclosures of MI6 secrets to newspapers and then in relation to the publication of his tell-all book about his adventures as a spy. Despite being convicted in the first instance, the CPS declined to prosecute in the second instance due to the likely revelation of “sensitive matters” in the course of a trial.

This pinpoints the practical dilemma in a prosecution for leaking State secrets. The CPS is only likely to prosecute where it (and the intelligence services) is confident it will achieve sufficient restrictions concerning the publicity of the prosecution; in the aftermath of one unauthorised disclosure of secret information, can a second public airing be risked? The courts in Shayler and Tomlinson’s trials were willing to place restrictions around the disclosure of further State secrets, but such restrictions would be more difficult to justify where, for example, an agent claims that the disclosures were made because he wanted to expose misconduct, or even criminality, from within his own ranks. In such cases, and as highlighted by the Lord Chief Justice in the case of Erol Incedal, the judiciary must stand firm in ensuring that public accountability of the intelligence services is not avoided, and that the right balance is struck between security and transparency.

From Russia with love

The absence of a public interest defence under UK law mirrors the position in the US. That is the reason why Edward Snowden finds himself sending postcards home from Russia, unable to enter the US or UK without risk of incarceration. The public interest defence, if it was available under US law, would no doubt have been deployed by Snowden, who has stated that he is: “…willing to sacrifice all of that because I can’t in good conscience allow the US government to destroy privacy, internet freedom and basic liberties for people around the world with this massive surveillance machine they’re secretly building.”

Snowden has reportedly offered to serve time in prison in the US as part of a plea deal but says that the US authorities have not responded. Snowden could of course have chosen to seek the official route of whistleblower, benefitting from whistleblower protections in the process, but has said that such protections would have been inadequate. As he sees it, he had no option but to make the disclosure in order to highlight the extent of Government surveillance, which in his view was the only way to serve the wider public interest.

The prosecution of a Snowden-type figure in the UK for leaking State secrets would be a troubling prospect for the intelligence services. They would be concerned not only about ensuring that any further damaging information disclosed during any trial was not reported on, but that defendants who can portray themselves as courageous whistleblowers are likely to elicit sympathy from a jury, even though the public interest defence no longer exists. The spectre of the Clive Ponting trial still looms large. The risks of prosecuting errant spies, even treacherous double agents, remain as big a problem today as they were in the Cold War.  Any kind of secret criminal trial process needs to command public confidence and respect and it is not yet clear how this can ever be achieved in a society underpinned by some immutable fundamental freedoms.